MAX220–MAX249 - Instituto Politécnico de Setúbal

Transcription

Instituto Politécnico de Setúbal
Escola Superior de Tecnologia
de Setúbal
Controlo de um sistema articulado com dois graus de liberdade
Pedro Silva
Nº: 4064
Luís Rita
Nº: 3468
Projecto final para obtenção do grau de Bacharel em Engenharia de Electrónica
e Computadores
Outubro de 2003
Escola Superior de Tecnologia de Setúbal
Projecto Final de Curso
I
Projecto Final realizado sob a orientação do
Professor António Abreu
Departamento de Engenharia Electrotécnica
II
RESUMO
Este trabalho tem como objectivo a construção e controlo de um sistema com 2
graus de liberdade: azimute e elevação.
O controlo incide sobre 2 motores passo-a-passo, e a informação na qual se
baseia o controlo é a luminosidade proveniente de quatro sensores.
Assim, o sistema procura e segue fontes de luminosidade.
PALAVRAS CHAVE
•
Sensor
•
Conversor
•
Controlo
•
Motor passo-a-passo
III
ABSTRACT
The objective of this is the construction and control of a system with two
degrees of freedom: azimuth and elevation.
The control goes straight to two engines step by step, and is based on the
brightness of four sensors.
So, the system searches for and follows the source of the brightness.
KEYWORDS
•
Sensor
•
Converter
•
Control
•
Engine step by step
IV
AGRADECIMENTOS
Desejamos prestar os nossos agradecimentos ao nosso orientador Prof. António
Abreu, por se ter empenhado na orientação deste projecto muito para além do que era a
sua obrigação.
Desejamos também expressar os nossos agradecimentos ao Sr. Luís Manuel
Jesus da Silva e ao Sr. Manuel Moita Rita, por todo o apoio técnico que nos prestaram e
pelas proveitosas trocas de ideias que tiveram connosco.
Um agradecimento muito especial para as nossas famílias, que tiveram sempre
ao nosso lado nos momentos de maiores dificuldades.
Finalmente, desejamos agradecer à ESTS pelos meios que colocou à nossa
disposição, que tornaram possível a conclusão deste projecto.
V
ÍNDICE GERAL
Página
1 – INTRODUÇÃO ...........................................................................................................1
1.1 – Descrição do Trabalho..........................................................................................1
1.2 – Organização do Projecto.......................................................................................2
2 – DIAGRAMA DE BLOCOS IMPLEMENTADO .......................................................3
3 – SENSORES .................................................................................................................5
3.1 – Fotodíodo..............................................................................................................5
3.2 – Fototransístor ........................................................................................................7
3.3 – LDR (light dependent resistor) ............................................................................9
3.4 – Disposição dos Sensores.....................................................................................12
3.5 – Opções Tomadas ................................................................................................17
3.5.1 – Três sensores ...............................................................................................17
3.5.2 – Cinco sensores.............................................................................................18
3.5.3 – Quatro sensores ...........................................................................................18
4 – CONTROLO DO SISTEMA ....................................................................................21
4.1 – Controlo ON/OFF...............................................................................................21
5 – ADC...........................................................................................................................23
5.1 MX7828.................................................................................................................23
6 – MOTORES PASSO-A-PASSO.................................................................................24
6.1 – Descrição do Motor Passo-a-Passo ....................................................................24
6.2 – O Meio Passo......................................................................................................24
6.3 – Princípio de Funcionamento ...............................................................................25
7 – DRIVERS ..................................................................................................................29
7.1 – SAA1042 ............................................................................................................29
7.2 – Esquema Eléctrico do Driver..............................................................................30
8 – SISTEMA ARTICULADO .......................................................................................32
9 – COMPORTAMENTO DA CABEÇA EM RELAÇÃO AO ESTÍMULO ................35
9.1 – Um Eixo de Cada Vez Contra Dois Eixos em Simultâneo ................................35
9.2 - Descrição do Funcionamento do Sistema ...........................................................37
9.3 - Inicialização do Sistema......................................................................................38
10 – SOFTWARE DE APLICAÇÃO .............................................................................42
11 – TESTES PRÁTICOS...............................................................................................44
12 – APLICAÇÕES ........................................................................................................47
13 – MELHORAMENTOS FUTUROS..........................................................................48
14 – CONCLUSÕES .......................................................................................................49
15 – REFERÊNCIAS BIBLIOGRÁFICAS ....................................................................50
ANEXOS
VI
ÍNDICE DE FIGURAS
Página
Figura 1.1 – Sistema articulado a controlar. ......................................................................1
Figura 2.1– Diagrama de blocos do sistema implementado. .............................................3
Figura 3. 1 – Configuração básica de polarização.............................................................5
Figura 3. 2 – Corrente inversa em função da luz, retirada da referência [3]. ....................6
Figura 3. 3 – Símbolo do Fotodíodo..................................................................................6
Figura 3. 4 – Curva Característica do Fotodíodo, de [3]. ..................................................7
Figura 3. 5 - Circuito exemplo do fototransístor, de [3]....................................................8
Figura 3. 6 – Símbolo do fototransístor. ............................................................................8
Figura 3. 7 – Curva Característica do fototransístor, de [3]. .............................................9
Figura 3. 8 – Símbolo da LDR. .......................................................................................10
Figura 3. 9 – Medição experimental da variação da tensão aos terminais da LDR em
função da variação da luz ambiente.........................................................................11
Figura 3. 10 – Esquema eléctrico utilizado para medir a variação de luminosidade
apresentada na figura 3.9. ........................................................................................12
Figura 3. 11 – Disposição dos três sensores. ...................................................................13
Figura 3. 12 – Captura de luz. .........................................................................................13
Figura 3. 13 – Situação de luz focada..............................................................................14
Figura 3. 14 – Disposição de quatro sensores no sistema de rotação. .............................14
Figura 3. 15 – A cabeça segue a luz no sentido do sensor que está a captar maior
luminosidade............................................................................................................15
Figura 3. 17 – Disposição dos cinco sensores. ................................................................16
Figura 3. 18 – Movimento lateral. ...................................................................................16
Figura 3. 20 - Exemplo a com três sensores. ...................................................................17
Figura 3. 21 – Configuração de quatro sensores escolhida. ............................................19
Figura 3. 22 – Protecção da luz lateral. ...........................................................................20
Figura 3. 23 – Luz ambiente em função da luz máxima. ................................................20
Figura 4.1 – Esquema dos sensores em actuação. ...........................................................21
Figura 4. 2 – Resultado do controlo em função da entrada. ............................................22
Figura 5. 1 – Sinais de Controlo do ADC. ......................................................................23
Figura 6. 1 – Configuração de um motor passo-a-passo e disposição do rotor em função
da polaridade da alimentação do estator, retirada de [2]. ........................................26
Figura 6. 2 – Modelo de um motor passo-a-passo com 6 fios.........................................27
Figura 7. 1 – Esquema típico do SAA1042. ....................................................................29
Figura 7. 2 – Esquema eléctrico dos drivers do motor passo-a-passo.............................30
Figura 8. 1 – Sistema de contactos deslizantes................................................................32
Figura 8. 2 – Desmultiplicação de força..........................................................................34
VII
Figura 9. 1– Caminho percorrido pela cabeça analisando um eixo de cada vez. ............35
Figura 9. 2 – Caminho percorrido pela cabeça analisando os dois eixos em simultâneo.
.................................................................................................................................36
Figura 9. 3 – Placa de circuito impresso do controlo do sistema. ...................................37
Figura 9. 4 – Cabeça na posição inicial (0°)....................................................................38
Figura 9. 5 – Posição limite em elevação (180° ou -180°). .............................................39
Figura 9. 6 – Posição de 45°. ...........................................................................................40
Figura 9. 7 – Posição de -45°...........................................................................................41
Figura 10. 1 – Menu Principal da aplicação desenvolvida. .............................................42
Figura 10. 2 – Gráfico em tempo real dos valores lidos..................................................43
Figura 11. 1 – Gráfico da resposta com um eixo de cada vez. ........................................44
Figura 11. 2 – Gráfico da resposta com os dois eixos em simultâneo.............................45
Figura 11. 3 – Gráfico da resposta do sistema em três situações idênticas. ....................46
VIII
ÍNDICE DE TABELAS
Página
Tabela 6. 1 – Sequência de passos de um motor passo-a-passo......................................28
Tabela 7. 1 – Lista de entradas e saídas do Driver. .........................................................31
IX
1 – INTRODUÇÃO
1.1 – Descrição do Trabalho
Este projecto tem como finalidade a construção e o controlo de um sistema
articulado semelhante a uma cabeça, i.e., com uma parte fixa (o ombro) e uma parte
móvel com dois graus de liberdade: azimute e elevação (cabeça 1 ), como se pode ver na
figura 1.1, de modo a que a cabeça aponte para a zona que corresponda ao valor
máximo de uma variável, neste caso, a luminosidade.
Figura 1.1 – Sistema articulado a controlar.
Para isso foi desenhado um protótipo com base nos suportes para câmaras de
vídeo em aplicações de vigilância.
A escolha dos sensores, conversor e microcontrolador a utilizar foi uma tarefa
relativamente cuidadosa, pois dos componentes escolhidos dependem muitos factores.
O desenvolvimento do sistema prosseguiu com o estabelecimento do
comportamento da cabeça em função da informação de luminosidade, bem como o
melhoramento global, por via experimental.
Todos os estudos e resultados obtidos durante este projecto podem ainda ser
analisados através da seguinte página: http://ltodi.est.ips.pt/aabreu/cabeca.html.
1
Faltando somente a inclinação para que seja semelhante a uma cabeça
1
1.2 – Organização do Projecto
Este projecto encontra-se organizado em 15 capítulos. Assim, neste primeiro
capítulo é feita uma breve introdução do projecto, bem como a forma como este
documento se encontra organizado.
No capítulo 2 é descrito o diagrama de blocos implementado, para se ter uma
melhor visualização dos blocos constituintes do projecto.
No capítulo 3 apresentam-se os tipos de sensores que reagem à luminosidade, e
o porquê da utilização das LDRs. É ainda feito um estudo das possíveis disposições dos
sensores, bem como do número de sensores necessários.
No capítulo 4 é abordada a forma como o sistema é controlado, enquanto que no
capítulo 5 é descrita como é realizada a conversão analógico – digital.
Por outro lado, no capítulo 6 é feito um estudo sobre mo tores passo-a-passo,
assim como uma caracterização mais pormenorizada dos motores utilizados. No
capítulo 7 é apresentada a forma como foram construídos os drivers para controlar os
motores.
No capítulo 8 são apresentados os factores tidos em conta aquando da realização
do sistema articulado, enquanto que no capítulo 9 é caracterizado o comportamento da
cabeça em relação ao estímulo, bem como a comparação do funcionamento da mesma
quando o controlo incide num eixo de cada vez e nos dois eixos ao mesmo tempo.
No capítulo 10 é mostrado como funciona uma pequena aplicação de
visualização das variáveis do sistema, e no capítulo 11 são feitos os testes práticos do
comportamento da cabeça em relação a vários estímulos, utilizando para tal o software
de aplicação.
No capítulo 12 apresentam-se algumas aplicações deste projecto, enquanto que
no capítulo 13 apontam-se alguns melhoramentos possíveis.
Por fim nos capítulos 14 e 15 são apresentadas as conclusões de projecto, bem
como algumas referências bibliográficas.
2
2 – DIAGRAMA DE BLOCOS IMPLEMENTADO
O diagrama apresentado na figura 2.1 específica todos os blocos constituintes do
projecto, assim como as ligações entre cada um deles.
Figura 2.1– Diagrama de blocos do sistema implementado.
O bloco “Sensores” diz respeito ao conjunto de Sensores, tendo como função
captar a luminosidade ambiente. Esta luminosidade que é enviada para o bloco “ADC”,
sob a forma de tensão.
O bloco “ADC” é constituído por uma conversor analógico/digital que recebe os
valores provenientes do bloco “Sensores”. Sempre que o bloco “Microcontrolador” o
entenda, o “ADC” converte os valores, e envia-os para o mesmo, para que possam ser
processados.
O bloco “Microcontrolador” controla ainda 2 drivers, para os motores. Este
bloco, sempre que necessário, faz um pedido ao bloco “ADC” para que este converta os
3
valores dos sensores, e depois de processar a informação, envia as ordens de comando
para o bloco “Motores”, através dos drivers.
O bloco “Motores” é constituído por dois motores passo-a-passo, e tem como
única função provocar o movimento do sistema articulado, para que este siga o foco de
luz.
Após esta breve introdução, é apresentado um estudo mais aprofundado de como
estes blocos interagem entre si, assim como a sua constituição.
4
3 – SENSORES
Para a escolha dos sensores de luminosidade a utilizar foi realizado um estudo
sobre três tipos de sensores: fotodíodos, fototransístores e LDRs 2 .
3.1 – Fotodíodo
É um dispositivo semicondutor de junção P-N, construído de forma especial, de
modo a possibilitar a utilização da luz como factor determinante no controlo de corrente
eléctrica. A sua configuração básica de polarização é apresentada na figura 3.1. De notar
que este se encontra polarizado inversamente.
A aplicação de luz na junção P-N provoca uma transferência de energia das
ondas de luz incidentes (na forma de fotões) para a estrutura atómica, aumentando com
isto, o número de portadores minoritários e consequentemente o nível de corrente
inversa.
Uma vantagem importante neste dispositivo é o de a corrente inversa variar
proporcionalmente com a luminosidade, como se pode constatar na figura 3.2.
Figura 3. 1 – Configuração básica de polarização.
2
Resistência dependente da luz
5
Figura 3. 2 – Corrente inversa em função da luz, retirada da referência [3].
Símbolo:
Figura 3. 3 – Símbolo do Fotodíodo.
Constituição física:
É composto por duas pastilhas de silício como num díodo semicondutor normal.
A diferença está no tamanho das pastilhas que são maiores que a dos díodos
convencionais, além de existir uma “janela”, que possibilita a incidência dos raios
luminosos na junção.
Características:
•
Corrente inversa e o fluxo luminoso possuem relação quase linear.
•
Resposta (velocidade) é muito mais rápida que a LDR.
•
Sensível a luz visível, infravermelho e ultravioleta.
6
Curva Característica:
Figura 3. 4 – Curva Característica do Fotodíodo, de [3].
Aplicações:
•
Medir a intensidade luminosa (fotografia);
•
Detecção de sinais luminosos de alta- frequência.
3.2 – Fototransístor
O fototransístor é um dispositivo que funciona baseado no fenómeno da
fotocondutividade. Como nas outras células fotocondutoras, a incidência de luz (fotões)
provoca o surgimento de buracos na vizinhança da junção base-colector. Esta tensão fa z
com que os buracos se “movam” para o emissor, enquanto os electrões passam do
emissor para a base. Isto provocará um aumento da corrente de base, o que por
consequência implicará um aumento da corrente de colector ß vezes (Ic = ß . IB), sendo
este aumento proporcional à intensidade de luz incidente.
Como a base está normalmente desligada, a corrente que circula por ela
dependerá apenas da luz incidente. Assim, na ausência de luz, a corrente de base será
zero e o fototransístor está ao corte, resultando na tensão do colector igual à tensão de
polarização Vcc, como se ilustra na figura 3.5. Quando há luz incidindo sobre o
fototransístor, a tensão no colector irá diminuir devido ao aumento da corrente.
7
Na escolha de um fototransístor para uma dada aplicação, precisamos de
observar a sua sensibilidade à frequência da radiação utilizada (tipo de luz), a corrente
que ele fornece e a tensão máxima que pode ser aplicada entre o colector e o emissor.
Figura 3. 5 - Circuito exemplo do fototransístor, de [3].
Símbolo:
Figura 3. 6 – Símbolo do fototransístor.
Ligação:
O terminal de base poderá ou não estar electricamente ligado. Nas aplicações
normais, os fototransístores são utilizados com a base livre (NC). A corrente que circula
entre o colector e o emissor depende da luz e é então aproveitada para controlo de um
circuito.
8
Curva Característica:
Figura 3. 7 – Curva Característica do fototransístor, de [3].
Aplicações:
•
Equipamentos de controlo de luz
•
Leitura de cartões
•
Acopladores ópticos
3.3 – LDR (light dependent resistor)
Existem substâncias que alteram a sua resistência em função da quantidade de
luz que recebem. Os fotões de luz visível que a substância recebe retiram os electrões
das órbitas, aumentando assim o número de electrões livres e facilitando a condução de
corrente.
O sulfato de cádmio (Cds) é uma das substâncias utilizadas para o fabrico de
Ldrs.
9
Símbolo:
Figura 3. 8 – Símbolo da LDR.
Características:
•
Não são componentes polarizados.
•
Dissipam calor como as resistências.
•
A capacidade é directamente proporcional à área de sensibilidade, ou seja,
quanto maior for a superfície de incidência da luz, mais sensível é a LDR, e por
outro lado possibilita o controlo de correntes mais intensas por parte desta.
•
A resistência da LDR varia com a luz do seguinte modo: 1MΩ<R(ambiente
escuro)<10MΩ e 75Ω<R(ambiente iluminado)< 500Ω
•
Resposta espectral:
o A sensibilidade da LDR é maior para comprimentos de onda que
reproduzem a cor vermelha, tendendo um pouco para a laranja (6800
Angstron);
o É sensível a comprimentos de onda que o olho humano não percebe,
como o infravermelho (7000 a 7500 Angstron)
•
Resposta de actuação:
o A LDR é um dispositivo lento. Estando todo iluminado, aquando da
retirada da fonte de luz e em comparação com o fotodíodo/fototransístor,
denota-se uma demora até que a sua resistência volte ao valor máximo.
Assim sendo, a sua aplicação não é viável, por exemplo, em leitura de código de
barras. No entanto, pode aplicar-se em brinquedos, detectores de nível de iluminação,
10
sensores de luz ambiente, etc., visto não ser necessária uma verificação rápida da
variação da resistência com a luz.
Portanto, após um estudo teórico e alguns testes experimentais, o sensor
escolhido para leitura da quantidade de luz foi a LDR.
As razões principais da desta escolha têm por base as seguintes características
das LDR: são sensores que têm um tempo de resposta aceitável à detecção de luz, na
ordem dos 33ms, como se pode ver na figura 3.9; e não variam de uma forma brusca
com a variação de luz, ao contrário dos fotodíodos e dos fototransístores.
Figura 3. 9 – Medição experimental da variação da tensão aos terminais da LDR em função da
variação da luz ambiente.
11
Para se chegar ao resultado da figura foi implementado o circuito da figura 3.10.
Figura 3. 10 – Esquema eléctrico utilizado para medir a variação de luminosidade apresentada na
figura 3.9.
Este funciona como um divisor de tensão, em que a tensão de saída varia
directamente com a variação da resistência na LDR.
Vo =
R1
Vi
R1 + LDR
3.4 – Disposição dos Sensores
O número mínimo de sensores para que a cabeça consiga seguir um foco de luz,
num espaço a 2 dimensões 3 , é três, com a disposição apresentada na figura 3.11.
Contudo, esta opção introduz uma maior complexidade ao nível do controlo, pois não se
pode associar a cada sensor uma direcção.
θ , Elevação – ϕ
3
Azimu te –
12
Figura 3. 11 – Disposição dos três sensores.
Quando é detectada luz pelo grupo de sensores, a informação é processada
resultando um movimento composto, i.e., movimento nos 2 eixos, tal como se ilustra na
figura 3.12. Relativamente a essa figura há que referir que a cor dos círculos representa
a luminosidade que cada sensor recebe, ou seja, quanto mais claro for círculo, maior
luminosidade está a receber o sensor.
Figura 3. 12 – Captura de luz.
Nesta disposição considera-se que a cabeça está a apontar para o foco de luz
quando todos os sensores medirem a mesma luminosidade, tal como se ilustra na figura
3.13.
13
Figura 3. 13 – Situação de luz focada.
Por outro lado, a utilização de 4 sensores permite associar os dois sentidos dos
dois eixos de rotação ( ϕ e θ ) a cada sensor, de acordo com o ilustrado na figura 3.14.
Figura 3. 14 – Disposição de quatro sensores no sistema de rotação.
Para o seguimento do foco de luz, os sensores são analisados dois a dois,
avaliando-se os semi-eixos em que os movimentos devem ser feitos. Por exemplo, a
diferença entre os sensores de topo e de baixo, permite determinar qual o sentido de
movimento a realizar no eixo ϕ .
14
Figura 3. 15 – A cabeça segue a luz no sentido do sensor que está a captar maior luminosidade.
Para se poder dizer que a posição do foco de luz está devidamente determinada,
todos os sensores devem receber a mesma intensidade de luz, ver figura 3.16.
No caso de serem utilizados cinco sensores, a disposição a realizar seria a que se
apresenta na figura 3.17.
15
Figura 3. 17 – Disposição dos cinco sensores.
Os quatro sensores dispostos em quadrado correspondem a cada uma das
direcções possíveis de movimento, tal como no caso anterior. O sensor que captar maior
luminosidade determina qual o sentido e direcção em que a cabeça se deve mover (ver
figura 3.18).
Figura 3. 18 – Movimento lateral.
Neste caso, o sensor do meio permitiria o reconhecimento da cabeça focada, ou
seja, quando o sensor do meio apresenta o maior valor, então a cabeça está focada (ver
figura 3.19).
O quinto sensor, como se verá, para além de ser redundante piora o desempenho
do sistema, como tal é dispensado.
16
3.5 – Opções Tomadas
3.5.1 – Três sensores
Como já foi referido, o uso de três sensores complica o processo de controlo do
sistema, assim apesar de não ter sido testado na prática foi realizado o seguinte estudo
teórico:
Considere-se a seguinte situação:
Figura 3. 20 - Exemplo a com três sensores.
O movimento deve ser proporcional a:
cos( −30) = 0,89 → no eixo φ

 sen( −30) = −0,5 → no eixo ϕ
17
Agora, há que transformar 0,89 e -0,5 em quantidades inteiras. Primeiro vai-se
convencionar que basta trabalhar com uma casa decimal.
Seja:
m = min(| 0,87 |; | −0,5 |) = 0,5
0,87 0,87
=
= 1,74;
m
0,5
0.5 0.5
=
=1
m
0,5
Como é que se anda 1,74 unidades no eixo ? e 1 no eixo ϕ ? Tem que se definir
a precisão que se quer. Para isso pode-se definir os seguintes pares de movimento: (1,1),
(2,3), (3,5), (4,7); Caso se continuasse obter-se- ia uma maior precisão, mas o
movimento seria maior. O movimento (3,5) talvez seja um bom ponto de equilíbrio.
3.5.2 – Cinco sensores
Foi inicialmente testado o funcionamento da cabeça com cinco sensores.
Contudo chegou-se à conclusão de que esta disposição tinha o inconveniente de não
reagir a pequenos movimentos do foco, ou seja, enquanto o sensor do meio retornar o
maior valor, a cabeça não se mexe, pois é considerada focada podendo esse sensor
captar mais luminosidade.
3.5.3 – Quatro sensores
Assim, e para eliminar os problemas surgidos nas configurações já apresentadas,
a escolha recaiu na configuração com quatro sensores, como se pode ver na figura 3.20.
18
.
Figura 3. 21 – Configuração de quatro sensores escolhida.
Foi também colocada a hipótese da utilização de um sensor na parte traseira da
cabeça, para apanhar fontes de luz que aparecessem na posição diametralmente oposta à
dos sensores (i.e., na nuca). Esta opção apresenta a desvantagem de necessitar de mais 1
sensor. Com efeito quando passa algum tempo sem que a cabeça capte luz que não seja
a ambiente, esta executa uma procura sistemática, prescutando todo o espaço
envolvente.
Outra opção tomada relativamente aos sensores teve a ver com o ângulo de
captura das LDR, que é muito grande. Para isso foram colocadas umas protecções em
todos os sensores, tal como se apresenta na figura 3.21, para que a luz vinda
lateralmente não seja captada. Deste modo, cada sensor indica a presença de fontes de
luz que estejam na direcção do seu eixo longitudinal.
19
Figura 3. 22 – Protecção da luz lateral.
Uma das contrariedades na realização do trabalho foi a existência de luz
ambiente forte. Quando a luz ambiente é muito forte, é necessário que o foco de luz seja
ainda mais forte para que seja reconhecido como tal. Para além disso, quanto mais perto
o nível da luz ambiente estiver do nível de saturação da LDR, mais difícil, se não
mesmo impossível, é a detecção e seguimento do foco (ver figura 3.22).
Figura 3. 23 – Luz ambiente em função da luz máxima.
Portanto temos:
O domínio da variável luminosidade captada pelo sensor, que se determina
subtraindo o nível de luz ambiente da luz máxima captada, deve ser tão grande quanto
possível, isto é, a luz ambiente deve ser baixa e o foco deve emitir luz forte.
20
4 – CONTROLO DO SISTEMA
4.1 – Controlo ON/OFF
Para o controlo do sistema em causa foi utilizado um controlo ON/OFF, ou seja,
são lidos os valores provenientes dos sensores (figura 4.1), e é feita uma subtracção. Se
o valor da subtracção for superior a um dado valor (Sensibilidade), então o motor que
comanda a elevação move-se um passo (ON) no sentido indicado pelo sinal da
subtracção. Caso contrário, o sistema não mexe (OFF). O valor de sensibilidade é
ajustado experimentalmente.
Figura 4.1 – Esquema dos sensores em actuação.
Com vista a resumir o texto, só se faz a explicação do cálculo do movimento
para o eixo ϕ , ou seja, só se considera os sensores 1 e 2, de acordo com a figura 4.1. Os
cálculos para o restante eixo são semelhantes.
Considere-se que:
∆S = Sensor1 − Sensor 2
E que o comportamento do sistema é dado por:
∆S < Sensibilid ade ⇒ OFF

∆S ≥ Sensibilid ade ⇒ ON
O que controla o sentido de rotação, cima ou baixo, é o sinal de ∆S .
21
Assim:
∆S < 0 ⇒ Cima
∆S > 0 ⇒ Baixo
Como conclusão pode dizer-se que:
Figura 4. 2 – Resultado do controlo em função da entrada.
OFF ⇒ 0

resposta = ON ∧ Cima ⇒ 1
ON ∧ Baixo ⇒ −1

22
5 – ADC
5.1 MX7828
Para transformar os valores de tensão provenientes das LDR em informação
digital, é necessária a utilização de um conversor analógico para digital.
Assim e após um estudo de mercado, foi escolhido o ADC MX7828, cujo
datasheet se encontra no anexo A.3, dado ter uma velocidade de conversão elevada, na
ordem dos 2,5µs por canal, e por ter 8 canais, o que é importante quando se usam
muitos sensores. É um ADC de 8 bits com interface paralelo.
Este ADC possui 4 sinais de controlo para fazer-se a conversão de analógico
para digital: o /CS (chip-select), /RD (read), RDY (ready) e /INT (interrupt output).
Como se pode comprovar pela figura 4.1, todos os sinais são inicialmente
colocados a 1, em seguida são colocados a 0 os sinais /CS, /RD pelo micro, e RDY e
/INT pelo ADC. A informação convertida fica disponível nos pinos correspondentes.
Por último, e para se poder realizar mais uma conversão, os sinais /RD, /INT, RDY e
/CS são colocados a 1.
O intervalo de tempo entre as activações de /CS e /RD não é tomado em
consideração porque é muito pequeno, o que é garantido pelo tempo que demoram as
instruções do microcontrolador.
Figura 5. 1 – Sinais de Controlo do ADC.
23
6 – MOTORES PASSO-A-PASSO
6.1 – Descrição do Motor Passo-a-Passo
Num motor passo-a-passo, como o próprio nome indica, o veio move-se uma
quantidade discreta, denominada passo, em resposta à aplicação de um sinal eléctrico
entre dois dos seus terminais. A velocidade com que o veio se move é função da taxa a
que se sucedem os passos. Assim, um motor passo-a-passo é um dispositivo síncrono.
Enquanto a diferença de potencial estiver aplicada nesses terminais, o veio do motor
está parado, fazendo uma força que se opõe a qualquer movimento imposto
exteriormente. Por outro lado, quando se remove a tensão entre os dois terminais, o veio
fica livre, deixando de fazer essa força, pelo que passa a ser fácil rodar o veio.
Um motor passo-a-passo dispõe no seu interior de diversos enrolamentos ou
bobinas. A quantidade de movimento angular num motor passo-a-passo ou o tamanho
do passo, é fixa e depende da configuração dos enrolamentos existentes. Nos dois
motores passo-a-passo utilizados no projecto, o que controla o azimute tem um passo de
4,5° e o que controla a elevação tem um passo de 1,82°. Em azimute são necessários
198 passos para se dar uma volta completa, enquanto que no eixo da elevação o motor
apenas necessita de dar 80 passos.
Azimute
360 ÷ 80 = 4,5° / passo
Elevação
360 ÷ 198 = 1,82° / passo
6.2 – O Meio Passo
O meio passo é conseguindo alimentando um enrolamento de cada vez em
alternância com a alimentação de ambos os enrolamentos. O meio passo tem o
inconveniente de que, por um lado tem-se que o torque varia de meio passo em meio
passo, dado que numas posições é alimentado um enrolamento e nas restantes são
alimentados dois enrolamentos, o que faz com que a força realizada não seja sempre a
mesma, mas por outro lado o meio passo tem a vantagem de permitir um controlo mais
24
fino, e, como tal, mais preciso. Como o principal objectivo do projecto é a precisão na
posição e não a força, decidiu-se utilizar o meio passo.
6.3 – Princípio de Funcionamento
Um motor é constituído por um rotor, que é a parte móvel, e por um estator, que
é a parte fixa. O veio do motor está acoplado ao rotor. A figura 6.1 a) pode ser
entendida como uma aproximação ao interior de um motor passo-a-passo.
Considere-se um motor com dois enrolamentos. Logo que seja aplicada uma
diferença de potencial aos terminais do motor, segundo a polaridade indicada na figura
6.1 b) e cuja grandeza não é importante, a passagem da corrente eléctrica cria nas
bobinas um campo magnético cuja polaridade é também apresentada na figura 6.1 b).
Dado que pólos diferentes atraem-se, então o veio do motor é levado para a posição
indicada, que é a única onde a distância entre os pólos opostos do rotor e do estator é
menor neste caso. Se a polaridade aos terminais do motor for invertida, como
evidenciado na figura 6.1 c), então o veio roda em sentido contrário ao da figura 6.1 b),
pois pólos iguais repelem-se. Contudo, após a rotação do rotor, essa força vai-se
transformar em força de atracção.
25
Figura 6. 1 – Configuração de um motor passo-a-passo e disposição do rotor em função da
polaridade da alimentação do estator, retirada de [2].
Existem vários tipos de motores passo-a-passo. Relativamente à constituição do
rotor, existem motores de relutância variável e de magneto permanente. Quanto à
configuração interna, existem os unipolares e os bipolares.
Os motores utilizados no projecto são motores passo-a-passo unipolares com
cinco fios, apresentando uma configuração idêntica à da figura 6.2; contudo, os
terminais Power1 e Power2 estão ligados interiormente entre si, ao contrário do que
acontece nos motores com seis fios.
26
Figura 6. 2 – Modelo de um motor passo-a-passo com 6 fios.
Os motores passo-a-passo podem funcionar em passo simples, em passo simples
com duas fases e em meio passo como se ilustra na tabela 6.1.
27
Tabela de sequência de passos
Sequência
Nome
Descrição
1a 2b 1b 2a
0 0 0 1
0 0 1 0
0 1 0 0
Cada enrolamento é alimentado de
Passo Simples cada
vez,
conseguindo-se
um
menor consumo de corrente.
1 0 0 0
Os enrolamentos são alimentados
0 0 1 1
0 1 1 0
1 1 0 0
1 0 0 1
Passo Simples dois a dois, daí o nome “Duas
Fases”.
Assim
temos
um
com
comportamento igual ao passo
Duas Fases
simples, mas com mais força. O
consumo de corrente é maio r
0 0 0 1
0 0 1 1
0 0 1 0
0 1 1 0
0 1 0 0
Funciona a partir das duas formas
Meio Passo
anteriores,
e
obtêm-se
uma
precisão maior. É de notar que a
1 1 0 0
sequência é constituída por oito
1 0 0 0
passos.
1 0 0 1
Tabela 6. 1 – Sequência de passos de um motor passo-a-passo.
28
7 – DRIVERS
7.1 – SAA1042
O SAA1042 é um driver para motores passo-a-passo. Este circuito integrado
possui 3 estados de entrada, 2 estados de saída e uma secção de lógica; suporta até
500mA, funciona com comandos CW/CCW, com meio passo ou passo completo.
Para isso foi utilizado o CI SAA1042, (ver anexo A.4) de forma a permitir um
controlo de direcção e velocidade com apenas dois pinos para cada motor (Clock e
CW/CCW), ver figura 7.1. A sua utilização é vantajosa se tivermos em consideração o
número de portos disponíveis pelo microcontrolador AT89C51 (ver anexo A.1), caso
contrário eram necessários 8 pinos.
Figura 7. 1 – Es quema típico do SAA1042.
Outra vantagem prende-se com o facto de se trabalhar em meio passo, o que
aumenta a precisão em 100%. Contudo, este CI é limitado ao nível da corrente
disponibilizada para o motor. Assim fo i utilizado um circuito simples com transístores
de potência, de modo a permitir maiores consumos no motor a partir da fonte de
alimentação. Neste caso, o sinal gerado pelo CI é apenas de controlo.
29
Um problema que se coloca é devido à elevada corrente que o motor necessita
para trabalhar correctamente, na ordem de 1A/1,5A. O regulador normalmente utilizado,
e facilmente adquirível no mercado, é o 7805C, cujo datasheet se encontra no anexo
A.5, que suporta uma corrente máxima de 1,2A. Na impossibilidade prática de se
encontrar outra solução optou-se pelo uso de dois desses reguladores em paralelo, sendo
necessário proceder à escolha de dois reguladores o mais iguais entre si, de uma forma
experimental, para que a distribuição da corrente pelos dois fosse semelhante.
Devido aos valores de corrente que percorrem os reguladores serem muito
próximos do valor máximo, optou-se por se utilizar dissipadores como forma de facilitar
a dissipação do calor gerado por efeito de Joule e assim aumentar o seu tempo de vida.
7.2 – Esquema Eléctrico do Driver
Figura 7. 2 – Esquema eléctrico dos drivers do motor passo-a-passo.
30
A tabela 7.1 mostra a lista de entradas e saídas do esquema da figura 7.2.
Tabela de Entradas/Saídas
Pino
Nome
U9.1
GND
U9.2
+5V
Descrição
Massa do sistema.
+5 Volt, sai directamente dos reguladores para
alimentar o motor.
U9.3
VI
U10.1
Dir_x
Alimentação do sistema.
Sinal proveniente do microcontrolador que
define a direcção de rotação.
U10.2 Freq_x
Sinal proveniente do microcontrolador que
controla a velocidade de rotação.
Enrolamento do motor. Quando o transístor Q8
U10.3
L4
recebe um sinal do SAA1042, este pino fica
ligado á massa.
U11.1
L3
ligado á massa.
U11.2
L2
ligado á massa.
U11.3
L1
ligado á massa.
Tabela 7. 1 – Lista de entradas e saídas do Driver.
31
8 – SISTEMA ARTICULADO
O suporte utilizado para dar forma à cabeça foi desenhado tendo em conta os
suportes para vídeo vigilância, ver desenho no anexo G.
O tamanho deste foi bastante influenciado pelo tamanho dos motores passo-apasso disponíveis.
Um dos factores que foi tido em conta no projecto do suporte foi não haver
limitação na rotação da cabeça em azimute. Para isso foi utilizado um sistema de
transmissão da alimentação eléctrica através de contactos deslizantes (ver anexo C.3),
como se ilustra na figura 8.1.
Figura 8. 1 – Sistema de contactos deslizantes.
32
São utilizados contactos em cobre que apresentam uma resistência muito
pequena, praticamente nula, quando comparados com escovas de carvão, como chegou
a ser testado. Estas últimas possuíam uma resistência de 30O em repouso e em
movimento chegavam a valores na ordem dos 400O a 1KO, considerados inviáveis. A
sua utilização requeria que a fonte de alimentação debitasse uma tensão na ordem dos
10 a 11 Volt. Por outro lado, tinha-se o inconveniente de que a tensão que alimentava o
circuito não era estável, mas oscilante entre 3,5 e 5 Volt, consoante a resistência da
escova de carvão nessa altura.
Como os motores passo-a-passo utilizados não são iguais, necessitam de um
número diferente de passos para percorrerem 360º (198 passos em elevação e 80 passos
em azimute). Assim, foi implementado um sistema de desmultiplicação de forças
usando dois carretos de dimensões diferentes unidos por uma correia, para que o
número de passos em elevação fosse mais ou menos o mesmo que em azimute, como se
pode ver na figura 8.2.
Tendo o carreto acoplado ao motor um diâmetro de 41 milímetros e o do eixo 16
milímetros consegue-se um factor multiplicativo (F_Mul) de:
F _ Mul =
16
= 0,39
41
O que aplicado ao número de passos necessários passa a ser:
Passos = 198 × 0,39 ≈ 77
33
Figura 8. 2 – Desmultiplicação de força.
34
9 – COMPORTAMENTO DA CABEÇA EM RELAÇÃO AO ESTÍMULO
Para controlar a cabeça em resposta à luz foi utilizado o microcontrolador
AT89C51, cujo datasheet se encontra no anexo A.1. Este microcontrolador tem
internamente 4 Kbytes de memória flash, 128*8 Bytes de RAM interna, 32 linhas de
Entrada/Saída programáveis e 2 contadores de 16 bits.
9.1 – Um Eixo de Cada Vez Contra Dois Eixos em Simultâneo
A operação de seguimento da luz por parte da cabeça, não é uma operação muito
complexa, tendo sido pensada de modo a ser a mais precisa e rápida possível.
Inicialmente utilizou-se uma forma de controlo que trabalha um eixo de cada
vez, (ver figura 9.1), ou seja, só depois de alinhar em elevação e que se passa para o
alinhamento em azimute.
Caminho Percorrido
16
15
14
13
12
Azimute - Nº Passos
11
10
9
8
Caminho 1
7
6
5
4
3
2
1
0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Elevação - Nº Passos
Figura 9. 1– Caminho percorrido pela cabeça analisando um eixo de cada vez.
35
Esta abordagem apresenta 2 defeitos:
– O tempo total para o alinhamento corresponde à soma dos tempos para o
alinhamento em cada eixo.
– Quando está a alinhar em elevação não capta movimentos em azimute
Para eliminar estes defeitos, foi utilizado outro método, alinhando-se os 2 eixos
em simultâneo (ver figura 9.2).
Caminho Percorrido
16
15
14
13
12
Azimute - Nº Passos
11
10
9
8
Caminho2
7
6
5
4
3
2
1
0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Elevação - Nº Passos
Figura 9. 2 – Caminho percorrido pela cabeça analisando os dois eixos em simultâneo.
Resultados:
– Diminuição do tempo de focagem.
– Capta todos os movimentos do foco em todos os instantes.
36
9.2 - Descrição do Funcionamento do Sistema
O controlo da cabeça com base nos pares de sensores cima/baixo e
esquerda/direita, separadamente, é do tio ON/OFF. Assim, o microcontrolador recebe os
valores dos sensores através do ADC e realiza as subtracções como está descrito no
capítulo CONTROLO DO SISTEMA. Depois de realizada esta operação o
microcontrolador provoca o movimento dos motores, ficando o foco mais perto do
centro dos sensores. Para isso foi implementado o circuito eléctrico apresentado no
anexo B.2, assim como a respectiva placa de circuito impresso (ver anexo C.2), como se
ilustra na figura 9.3.
Figura 9. 3 – Placa de circuito impresso do controlo do sistema.
37
9.3 - Inicialização do Sistema
Sempre que o sistema é ligado é necessário que o grupo de sensores esteja
virado para cima (posição inicial - 0°, ver figura 9.4), para que o sistema possa saber a
posição exacta da cabeça a qualquer instante. Este aspecto é importante, pois só assim
se pode limitar a rotação em elevação, entre 180° e -180°, na figura 9.5 apresenta-se a
cabeça com orientação -180°. Caso a cabeça continuasse a rodar, o conjunto de fios que
se vê do lado esquerdo enrolar-se- iam em torno do eixo metálico.
É também importante saber a posição da cabeça por causa dos sensores que
controlam o azimute, o sentido que estes comandam deve ser trocado quando se passa
de um ângulo positivo para um negativo. Caso esta troca não aconteça, verifica-se que a
cabeça tem um comportamento normal quando está a trabalhar em ângulos positivos,
mas quando entra nos ângulos negativos, em vez de seguir a luz, afasta-se dela, no eixo
da azimute.
Figura 9. 4 – Cabeça na posição inicial (0°).
38
Figura 9. 5 – Posição limite em elevação (180° ou -180°).
Após os sensores estarem na posição de 0°, e o sistema ter sido inicializado,
inicia-se o reconhecimento da quantidade de luz ambiente. Este reconhecimento
acontece da seguinte forma: a cabeça desloca-se 45° em elevação, como se ilustra na
figura 9.6, em seguida dá uma volta de 360° em azimute, e depois volta à posição 0° em
elevação, durante estes movimentos, os valores dos sensores são guardados, o valor
mais elevado é considerado o valor de luz ambiente.
Só depois de o sistema ter realizado este reconhecimento da quantidade de luz
ambiente é que se pode dizer que a cabeça está em condições de seguir um foco de luz.
No caso de o sistema não detectar um foco de luz num período de 10 segundos, é
realizada uma pesquisa com vista à procurar fontes de luz que possam ter surgido na
zona de sombra dos sensores. Antes de a executar, a cabeça é colocada na posição 45°
(ver figura 9.6) ou -45° (ver figura 9.7), dependendo se esta se encontra no lado positivo
ou no lado negativo do eixo da elevação. Esta pesquisa consiste numa rotação de 360°
em azimute, durante a qual os valores dos sensores e respectiva posição são guardados.
39
Assim que a volta de pesquisa acabe, a cabeça, caso tenha encontrado alguma
luminosidade maior, desloca-se para o local onde essa se encontra.
Figura 9. 6 – Posição de 45°.
40
Figura 9. 7 – Posição de -45°.
41
10 – SOFTWARE DE APLICAÇÃO
Tendo em vista o controlo da cabeça através de um computador, ou apenas para
uma melhor visualização das variáveis envolvidas no processo, foi desenvolvida uma
aplicação em Visual Basic, cujo o código se apresenta no anexo E.
Esta aplicação é constituída basicamente por duas janelas apresentadas nas
figuras 10.1 e 10.2. A primeira permite iniciar e parar o processo, alterar valores de
referência, sensibilidade e visualizar os valores provenientes dos sensores. A outra tem
como única função permitir ao utilizador a visualização de um gráfico em tempo real e a
informação do desvio da cabeça em relação ao ponto de maior luminosidade.
Figura 10. 1 – Menu Principal da aplicação desenvolvida.
42
Figura 10. 2 – Gráfico em tempo real dos valores lidos.
43
11 – TESTES PRÁTICOS
Foram realizados alguns testes de forma a se poder avaliar o comportamento da
cabeça em função da luz recebida.
O primeiro teste é relativo ao tempo necessário para que a cabeça ficasse focada.
A figura 11.1, é relativa à estabilização de um eixo de cada vez ao passo que a figura
11.2 é relativa à estabilização dos dois eixos em simultâneo.
Constata-se que, como previamente mencionado, o sistema com estabilização
em dois eixos em simultâneo é mais eficiente.
Captura de Luz
25
20
15
10
Diferença da Luz
5
0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
Vertival
70
Horizontal
-5
-10
-15
-20
-25
-30
Amostra
Figura 11. 1 – Gráfico da resposta com um eixo de cada vez.
Na figura 11.1 pode-se ver que o número de amostras necessário para que a luz
se considere focada é aproximadamente 45, sendo necessárias cerca de 15 para
estabilização no eixo ϕ e 30 para estabilização no eixo ?. Tendo-se 20 amostras por
segundo, pode-se dizer que o sistema demora 2,25s a orientar-se para a luz.
44
Captura de Luz
30
25
20
15
Diferença da Luz
10
5
Elevação
0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
Azimute
70
-5
-10
-15
-20
-25
-30
Amostra
Figura 11. 2 – Gráfico da resposta com os dois eixos em simultâneo.
Na figura 11.2 pode-se ver que o número de amostras necessário para que a luz
se considere focada é aproximadamente 27. Tal como anteriormente, assumindo 20
amostras por segundo, verifica-se que são necessários 1,4s para se obter a focagem.
A experiência cujo o resultado se apresenta na figura 11.2 foi repetida diversas
vezes, para verificar se a cabeça tinha sempre o mesmo comportamento. Partindo
sempre do mesmo sítio e respondendo a um estímulo que se encontrava sempre no
mesmo lugar, verificou-se que a cabeça tem sempre o mesmo comportamento (ver
figura 11.3).
45
Captura de Luz
25
20
15
10
Diferença da Luz
5
Elevação1
Azimute1
Elevação2
0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
Azimute2
Elevação3
Azimute3
-5
-10
-15
-20
-25
Amostra
Figura 11. 3 – Gráfico da resposta do sistema em três situações idênticas.
46
12 – APLICAÇÕES
O sistema desenvolvido pode ser aplicado em algumas situações práticas.
Pode-se utilizar em células fotovoltaicas ou painéis de aquecimento de água,
com orientação solar e assim ter-se um maior aproveitamento da energia solar.
Em sistemas de vigilância, trocando o tipo de sensores a utilizar para sensores
PIR, pode-se aplicar em sistemas de detecção e seguimento de pessoas.
47
13 – MELHORAMENTOS FUTUROS
Um dos aspectos que podem ser melhorados diz respeito ao valor de referência.
Com efeito, quando a cabeça começa a funcionar realiza uma volta para determinar a
luminosidade ambiente; a partir daí este valor permanece inalterado. Passa-se a ter um
problema pois a luz ambiente varia bastante durante o dia. Analise-se o seguinte caso: a
cabeça começa a funcionar às 9h numa sala de aula com três janelas viradas para o
nascente. O valor de referência obtido é 214. Passada uma hora foi notado que a cabeça
não respondia apenas ao foco de luz mas também respondia à luz exterior.
Uma das possibilidades para a resolução deste problema é fazer-se uma pesquisa
automática que procura o local de maior luminosidade. Caso este valor seja maior que a
referência, esta é actualizada por este valor. É assim conseguida uma referência
dinâmica ao longo do tempo.
È também possível a utilização de mais sensores pois existem disponíveis oito
canais de conversão analógico/digital.
Um melhoramento interessante está na remoção da limitação de rotação no eixo
de elevação.
48
14 – CONCLUSÕES
Este trabalho permitiu conhecer o funcionamento dos sensores de luz existentes
no mercado. Foi escolhida a LDR pois o seu comportamento é muito bom para o tipo de
sistema desenvolvido, pois, apesar de se considerar lento em relação a outros estudados
tem uma gama de variação maior.
Inicialmente o trabalho foi realizado com a utilização de cinco sensores, contudo
e após a realização de alguns testes, foi notada claramente a vantagem de se trabalhar
com quatro sensores pois conseguia-se “apanhar” muito melhor pequenos movimentos
do foco de luz.
A luz ambiente foi um dos factores que influenciou o desempenho do sistema.
Com efeito, a sua intensidade varia de local para local, assim como de hora para hora.
No que diz respeito aos motores passo-a-passo foi aproveitada a possibilidade da
utilização do meio passo para aumentar a precisão da cabeça. Outro factor que teve de
ser levado em consideração foi a velocidade máxima de funcionamento dos motores.
O facto de o sistema poder rodar em azimute sem constrangimentos, recorrendo
a contactos deslizantes, é uma característica positiva do trabalho. Foram testadas
escovas de carvão e de cobre, tendo-se observado os efeitos produzidos pelo movimento
na condutividade do carvão (aumento da resistência). As escovas de cobre apresentam
um bom contacto eléctrico, mas o atrito pode provocar desaparecimento das pistas no
longo prazo.
Foram testados dois métodos de seguimento da luz: alinhando um eixo de cada
vez e alinhando os dois eixos em simultâneo. Apesar de os dois serem eficazes o
segundo é superior, daí a escolha ter recaído sobre este.
49
15 – REFERÊNCIAS BIBLIOGRÁFICAS
[1]
A série MCS51 de Microcontroladores de oito bits da Intel, António Abreu,
Escola Superior de Tecnologia de Setúbal, Setembro, 1998
[2]
Motores passo-a-passo, António Abreu, Escola Superior de Tecnologia de
Setúbal, Setembro, 1998
[3]
Dispositivos Electrónicos e Teoria de Circuitos, Sexta Edição, Robert L.
Boylrstad e Louis Nashelsky, LTC Editora, 1996
[4]
http://209.41.165.153/stepper/Tutorials/UniTutor.htm
[5]
http://www.cefetpr.br/deptos/daelt/eletronica/disp_optoelet.pdf
[6]
http://www.imagingpg.com/products/products.asp?cat=30#88
[7]
http://www.arquimedes.net/sens/sensor_de_luz_2.htm
[8]
Electronic Devices And Circuits, First Edition, Michael Hassul e Don
Zimmerman, Prentice Hall, 1997
50
ANEXOS
ÍNDICE
ANEXO A – Datasheets
ANEXO A.1 – AT89C51
ANEXO A.2 – MAX233A
ANEXO A.3 – MX7828
ANEXO A.4 – SAA1042
ANEXO A.5 – 7805
ANEXO A.6 – BD243
ANEXO B – Esquemático
ANEXO B.1 – Drivers
ANEXO B.2 – Principal
ANEXO C – PCB
ANEXO C.1 – Drivers
ANEXO C.2 – Principal
ANEXO C.3 – Pistas para os contactos
deslizantes
ANEXO D – Programa do Microcontrolador
ANEXO D.1 – Sem Ligação ao PC
ANEXO D.2 – Com ligação ao PC
ANEXO E – Programa em Visual Basic
ANEXO F – Lista de material
ANEXO G – Desenho em Mechanical
ANEXO A – Datasheets
ANEXO A.1 – AT89C51
Features
• Compatible with MCS-51™ Products
• 4K Bytes of In-System Reprogrammable Flash Memory
•
•
•
•
•
•
•
•
– Endurance: 1,000 Write/Erase Cycles
Fully Static Operation: 0 Hz to 24 MHz
Three-level Program Memory Lock
128 x 8-bit Internal RAM
32 Programmable I/O Lines
Two 16-bit Timer/Counters
Six Interrupt Sources
Programmable Serial Channel
Low-power Idle and Power-down Modes
Description
The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K
bytes of Flash programmable and erasable read only memory (PEROM). The device
is manufactured using Atmel’s high-density nonvolatile memory technology and is
compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip
Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash
on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides
a highly-flexible and cost-effective solution to many embedded control applications.
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
RST
(RXD) P3.0
(TXD) P3.1
(INT0) P3.2
(INT1) P3.3
(T0) P3.4
(T1) P3.5
(WR) P3.6
(RD) P3.7
XTAL2
XTAL1
GND
44
43
42
41
40
39
38
37
36
35
34
P1.4
P1.3
P1.2
P1.1 (T2 EX)
P1.0 (T2)
NC
VCC
P0.0 (AD0)
P0.1 (AD1)
P0.2 (AD2)
P0.3 (AD3)
PQFP/TQFP
VCC
P0.0 (AD0)
P0.1 (AD1)
P0.2 (AD2)
P0.3 (AD3)
P0.4 (AD4)
P0.5 (AD5)
P0.6 (AD6)
P0.7 (AD7)
EA/VPP
ALE/PROG
PSEN
P2.7 (A15)
P2.6 (A14)
P2.5 (A13)
P2.4 (A12)
P2.3 (A11)
P2.2 (A10)
P2.1 (A9)
P2.0 (A8)
P1.5
P1.6
P1.7
RST
(RXD) P3.0
NC
(TXD) P3.1
(INT0) P3.2
(INT1) P3.3
(T0) P3.4
(T1) P3.5
6
5
4
3
2
1
44
43
42
41
40
P1.4
P1.3
P1.2
P1.1
P1.0
NC
VCC
P0.0 (AD0)
P0.1 (AD1)
P0.2 (AD2)
P0.3 (AD3)
PLCC
7
8
9
10
11
12
13
14
15
16
17
39
38
37
36
35
34
33
32
31
30
29
18
19
20
21
22
23
24
25
26
27
28
12
13
14
15
16
17
18
19
20
21
22
PO.4 (AD4)
P0.5 (AD5)
P0.6 (AD6)
P0.7 (AD7)
EA/VPP
NC
ALE/PROG
PSEN
P2.7 (A15)
P2.6 (A14)
P2.5 (A13)
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
(WR)P3.6
(RD) P3.7
XTAL2
XTAL1
GND
NC
(A8) P2.0
(A9) P2.1
(A10) P2.2
(A11) P2.3
(A12) P2.4
33
32
31
30
29
28
27
26
25
24
23
1
2
3
4
5
6
7
8
9
10
11
(WR)P3.6
(RD) P3.7
XTAL2
XTAL1
GND
GND
(A8) P2.0
(A9) P2.1
(A10) P2.2
(A11) P2.3
(A12) P2.4
P1.5
P1.6
P1.7
RST
(RXD) P3.0
NC
(TXD) P3.1
(INT0) P3.2
(INT1) P3.3
(T0) P3.4
(T1) P3.5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
AT89C51
Not Recommended
for New Designs.
Use AT89S51.
PDIP
Pin Configurations
8-bit
Microcontroller
with 4K Bytes
Flash
PO.4 (AD4)
P0.5 (AD5)
P0.6 (AD6)
P0.7 (AD7)
EA/VPP
NC
ALE/PROG
PSEN
P2.7 (A15)
P2.6 (A14)
P2.5 (A13)
Rev. 0265G–02/00
1
Block Diagram
P0.0 - P0.7
P2.0 - P2.7
PORT 0 DRIVERS
PORT 2 DRIVERS
VCC
GND
RAM ADDR.
REGISTER
B
REGISTER
PORT 0
LATCH
RAM
PORT 2
LATCH
FLASH
STACK
POINTER
ACC
BUFFER
TMP1
TMP2
PROGRAM
ADDRESS
REGISTER
PC
INCREMENTER
ALU
INTERRUPT, SERIAL PORT,
AND TIMER BLOCKS
PROGRAM
COUNTER
PSW
PSEN
ALE/PROG
EA / VPP
TIMING
AND
CONTROL
INSTRUCTION
REGISTER
DPTR
RST
PORT 1
LATCH
PORT 3
LATCH
PORT 1 DRIVERS
PORT 3 DRIVERS
OSC
P1.0 - P1.7
2
AT89C51
P3.0 - P3.7
AT89C51
The AT89C51 provides the following standard features: 4K
bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit
timer/counters, a five vector two-level interrupt architecture,
a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic
for operation down to zero frequency and supports two
software selectable power saving modes. The Idle Mode
stops the CPU while allowing the RAM, timer/counters,
serial port and interrupt system to continue functioning. The
Power-down Mode saves the RAM contents but freezes
the oscillator disabling all other chip functions until the next
hardware reset.
Port 2 pins that are externally being pulled low will source
current (IIL) because of the internal pullups.
Port 2 emits the high-order address byte during fetches
from external program memory and during accesses to
external data memory that use 16-bit addresses (MOVX @
DPTR). In this application, it uses strong internal pullups
when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the
contents of the P2 Special Function Register.
Port 2 also receives the high-order address bits and some
control signals during Flash programming and verification.
Port 3
Pin Description
VCC
Supply voltage.
GND
Ground.
Port 3 is an 8-bit bi-directional I/O port with internal pullups.
The Port 3 output buffers can sink/source four TTL inputs.
When 1s are written to Port 3 pins they are pulled high by
the internal pullups and can be used as inputs. As inputs,
current (IIL) because of the pullups.
Port 3 also serves the functions of various special features
of the AT89C51 as listed below:
Port 0
Port 0 is an 8-bit open-drain bi-directional I/O port. As an
output port, each pin can sink eight TTL inputs. When 1s
are written to port 0 pins, the pins can be used as highimpedance inputs.
Port Pin
Alternate Functions
P3.0
RXD (serial input port)
P3.1
TXD (serial output port)
Port 0 may also be configured to be the multiplexed loworder address/data bus during accesses to external program and data memory. In this mode P0 has internal
pullups.
P3.2
INT0 (external interrupt 0)
P3.3
INT1 (external interrupt 1)
P3.4
T0 (timer 0 external input)
Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program
verification. External pullups are required during program
verification.
P3.5
T1 (timer 1 external input)
P3.6
WR (external data memory write strobe)
P3.7
RD (external data memory read strobe)
Port 1
current (IIL) because of the internal pullups.
Port 1 also receives the low-order address bytes during
Flash programming and verification.
Port 2
Port 3 also receives some control signals for Flash programming and verification.
RST
Reset input. A high on this pin for two machine cycles while
the oscillator is running resets the device.
ALE/PROG
Address Latch Enable output pulse for latching the low byte
of the address during accesses to external memory. This
pin is also the program pulse input (PROG) during Flash
programming.
In normal operation ALE is emitted at a constant rate of 1/6
the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE
3
pulse is skipped during each access to external Data
Memory.
unconnected while XTAL1 is driven as shown in Figure 2.
There are no requirements on the duty cycle of the external
clock signal, since the input to the internal clocking circuitry
is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be
observed.
If desired, ALE operation can be disabled by setting bit 0 of
SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is
weakly pulled high. Setting the ALE-disable bit has no
effect if the microcontroller is in external execution mode.
Idle Mode
PSEN
In idle mode, the CPU puts itself to sleep while all the onchip peripherals remain active. The mode is invoked by
software. The content of the on-chip RAM and all the special functions registers remain unchanged during this
mode. The idle mode can be terminated by any enabled
interrupt or by a hardware reset.
Program Store Enable is the read strobe to external program memory.
When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine
cycle, except that two PSEN activations are skipped during
each access to external data memory.
It should be noted that when idle is terminated by a hard
ware reset, the device normally resumes program execution, from where it left off, up to two machine cycles before
the internal reset algorithm takes control. On-chip hardware
inhibits access to internal RAM in this event, but access to
the port pins is not inhibited. To eliminate the possibility of
an unexpected write to a port pin when Idle is terminated by
reset, the instruction following the one that invokes Idle
should not be one that writes to a port pin or to external
memory.
EA/VPP
External Access Enable. EA must be strapped to GND in
order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH.
Note, however, that if lock bit 1 is programmed, EA will be
internally latched on reset.
EA should be strapped to V C C for internal program
executions.
This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that require
12-volt VPP.
Figure 1. Oscillator Connections
C2
XTAL2
XTAL1
Input to the inverting oscillator amplifier and input to the
internal clock operating circuit.
C1
XTAL1
XTAL2
Output from the inverting oscillator amplifier.
GND
Oscillator Characteristics
XTAL1 and XTAL2 are the input and output, respectively,
of an inverting amplifier which can be configured for use as
an on-chip oscillator, as shown in Figure 1. Either a quartz
crystal or ceramic resonator may be used. To drive the
device from an external clock source, XTAL2 should be left
Note:
C1, C2 = 30 pF ± 10 pF for Crystals
= 40 pF ± 10 pF for Ceramic Resonators
Status of External Pins During Idle and Power-down Modes
Mode
Program Memory
ALE
PSEN
PORT0
PORT1
PORT2
PORT3
Idle
Internal
1
1
Data
Data
Data
Data
Idle
External
1
1
Float
Data
Address
Data
Power-down
Internal
0
0
Data
Data
Data
Data
Power-down
External
0
0
Float
Data
Data
Data
4
AT89C51
AT89C51
Figure 2. External Clock Drive Configuration
ters retain their values until the power-down mode is
terminated. The only exit from power-down is a hardware
reset. Reset redefines the SFRs but does not change the
on-chip RAM. The reset should not be activated before VCC
is restored to its normal operating level and must be held
active long enough to allow the oscillator to restart and
stabilize.
Program Memory Lock Bits
On the chip are three lock bits which can be left unprogrammed (U) or can be programmed (P) to obtain the
additional features listed in the table below.
Power-down Mode
In the power-down mode, the oscillator is stopped, and the
instruction that invokes power-down is the last instruction
executed. The on-chip RAM and Special Function Regis-
When lock bit 1 is programmed, the logic level at the EA pin
is sampled and latched during reset. If the device is powered up without a reset, the latch initializes to a random
value, and holds that value until reset is activated. It is necessary that the latched value of EA be in agreement with
the current logic level at that pin in order for the device to
function properly.
Lock Bit Protection Modes
Program Lock Bits
LB1
LB2
LB3
Protection Type
1
U
U
U
No program lock features
2
P
U
U
MOVC instructions executed from external program memory are disabled from
fetching code bytes from internal memory, EA is sampled and latched on reset,
and further programming of the Flash is disabled
3
P
P
U
Same as mode 2, also verify is disabled
4
P
P
P
Same as mode 3, also external execution is disabled
5
Programming the Flash
The AT89C51 is normally shipped with the on-chip Flash
memory array in the erased state (that is, contents = FFH)
and ready to be programmed. The programming interface
accepts either a high-voltage (12-volt) or a low-voltage
(V CC ) program enable signal. The low-voltage programming mode provides a convenient way to program the
AT89C51 inside the user’s system, while the high-voltage
programming mode is compatible with conventional thirdparty Flash or EPROM programmers.
The AT89C51 is shipped with either the high-voltage or
low-voltage programming mode enabled. The respective
top-side marking and device signature codes are listed in
the following table.
VPP = 12V
VPP = 5V
Top-side Mark
AT89C51
xxxx
yyww
AT89C51
xxxx-5
yyww
Signature
(030H) = 1EH
(031H) = 51H
(032H) =F FH
(030H) = 1EH
(031H) = 51H
(032H) = 05H
The AT89C51 code memory array is programmed byte-bybyte in either programming mode. To program any nonblank byte in the on-chip Flash Memory, the entire memory
must be erased using the Chip Erase Mode.
Programming Algorithm: Before programming the
AT89C51, the address, data and control signals should be
set up according to the Flash programming mode table and
Figure 3 and Figure 4. To program the AT89C51, take the
following steps.
1. Input the desired memory location on the address
lines.
2. Input the appropriate data byte on the data lines.
3. Activate the correct combination of control signals.
4. Raise EA/VPP to 12V for the high-voltage programming mode.
5. Pulse ALE/PROG once to program a byte in the
Flash array or the lock bits. The byte-write cycle is
self-timed and typically takes no more than 1.5 ms.
Repeat steps 1 through 5, changing the address
6
AT89C51
and data for the entire array or until the end of the
object file is reached.
Data Polling: The AT89C51 features Data Polling to indicate the end of a write cycle. During a write cycle, an
attempted read of the last byte written will result in the complement of the written datum on PO.7. Once the write cycle
has been completed, true data are valid on all outputs, and
the next cycle may begin. Data Polling may begin any time
after a write cycle has been initiated.
Ready/Busy: The progress of byte programming can also
be monitored by the RDY/BSY output signal. P3.4 is pulled
low after ALE goes high during programming to indicate
BUSY. P3.4 is pulled high again when programming is
done to indicate READY.
Program Verify: If lock bits LB1 and LB2 have not been
programmed, the programmed code data can be read back
via the address and data lines for verification. The lock bits
cannot be verified directly. Verification of the lock bits is
achieved by observing that their features are enabled.
Chip Erase: The entire Flash array is erased electrically
by using the proper combination of control signals and by
holding ALE/PROG low for 10 ms. The code array is written
with all “1”s. The chip erase operation must be executed
before the code memory can be re-programmed.
Reading the Signature Bytes: The signature bytes are
read by the same procedure as a normal verification of
locations 030H, 031H, and 032H, except that P3.6 and
P3.7 must be pulled to a logic low. The values returned are
as follows.
(030H) = 1EH indicates manufactured by Atmel
(031H) = 51H indicates 89C51
(032H) = FFH indicates 12V programming
(032H) = 05H indicates 5V programming
Programming Interface
Every code byte in the Flash array can be written and the
entire array can be erased by using the appropriate combination of control signals. The write operation cycle is selftimed and once initiated, will automatically time itself to
completion.
All major programming vendors offer worldwide support for
the Atmel microcontroller series. Please contact your local
programming vendor for the appropriate software revision.
AT89C51
Flash Programming Modes
RST
PSEN
EA/VPP
P2.6
P2.7
P3.6
P3.7
Write Code Data
H
L
H/12V
L
H
H
H
Read Code Data
H
L
H
L
L
H
H
Bit - 1
H
L
H/12V
H
H
H
H
Bit - 2
H
L
H/12V
H
H
L
L
Bit - 3
H
L
H/12V
H
L
H
L
Chip Erase
H
L
H/12V
H
L
L
L
Read Signature Byte
H
L
H
L
L
L
L
Mode
Write Lock
Note:
ALE/PROG
H
(1)
H
1. Chip Erase requires a 10 ms PROG pulse.
Figure 3. Programming the Flash
Figure 4. Verifying the Flash
+5V
+5V
AT89C51
A0 - A7
ADDR.
OOOOH/OFFFH
A8 - A11
P1
P2.0 - P2.3
AT89C51
VCC
P0
PGM
DATA
A0 - A7
ADDR.
OOOOH/0FFFH
P2.7
P2.0 - P2.3
P0
P2.6
ALE
PROG
P3.6
SEE FLASH
PROGRAMMING
MODES TABLE
P2.7
EA
VIH/VPP
3-24 MHz
PGM DATA
(USE 10K
PULLUPS)
ALE
P3.6
VIH
P3.7
P3.7
XTAL2
VCC
A8 - A11
P2.6
SEE FLASH
PROGRAMMING
MODES TABLE
P1
XTAL2
EA
XTAL1
RST
3-24 MHz
XTAL1
GND
RST
PSEN
VIH
GND
VIH
PSEN
7
Flash Programming and Verification Waveforms - High-voltage Mode (VPP = 12V)
PROGRAMMING
ADDRESS
P1.0 - P1.7
P2.0 - P2.3
VERIFICATION
ADDRESS
tAVQV
PORT 0
DATA IN
tDVGL
tAVGL
tGHDX
DATA OUT
tGHAX
ALE/PROG
tSHGL
tGLGH
VPP
tGHSL
LOGIC 1
LOGIC 0
EA/VPP
tEHSH
tEHQZ
tELQV
P2.7
(ENABLE)
tGHBL
P3.4
(RDY/BSY)
BUSY
READY
tWC
Flash Programming and Verification Waveforms - Low-voltage Mode (VPP = 5V)
PROGRAMMING
ADDRESS
P1.0 - P1.7
P2.0 - P2.3
VERIFICATION
ADDRESS
tAVQV
PORT 0
DATA IN
tDVGL
tAVGL
tGHDX
DATA OUT
tGHAX
ALE/PROG
tSHGL
tGLGH
LOGIC 1
LOGIC 0
EA/VPP
tEHSH
tEHQZ
tELQV
P2.7
(ENABLE)
tGHBL
P3.4
(RDY/BSY)
BUSY
tWC
8
AT89C51
READY
AT89C51
Flash Programming and Verification Characteristics
TA = 0°C to 70°C, VCC = 5.0 ± 10%
Symbol
VPP
(1)
Parameter
Min
Max
Units
Programming Enable Voltage
11.5
12.5
V
1.0
mA
24
MHz
IPP(1)
Programming Enable Current
1/tCLCL
Oscillator Frequency
tAVGL
Address Setup to PROG Low
48tCLCL
tGHAX
Address Hold after PROG
48tCLCL
tDVGL
Data Setup to PROG Low
48tCLCL
tGHDX
Data Hold after PROG
48tCLCL
tEHSH
P2.7 (ENABLE) High to VPP
48tCLCL
tSHGL
VPP Setup to PROG Low
10
µs
tGHSL(1)
VPP Hold after PROG
10
µs
tGLGH
PROG Width
tAVQV
Address to Data Valid
48tCLCL
tELQV
ENABLE Low to Data Valid
48tCLCL
tEHQZ
Data Float after ENABLE
tGHBL
PROG High to BUSY Low
tWC
Note:
Byte Write Cycle Time
1. Only used in 12-volt programming mode.
3
1
0
110
µs
48tCLCL
1.0
µs
2.0
ms
9
Absolute Maximum Ratings*
Operating Temperature.................................. -55°C to +125°C
*NOTICE:
Storage Temperature ..................................... -65°C to +150°C
Voltage on Any Pin
with Respect to Ground .....................................-1.0V to +7.0V
Maximum Operating Voltage ............................................ 6.6V
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and
functional operation of the device at these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect device
reliability.
DC Output Current...................................................... 15.0 mA
DC Characteristics
TA = -40°C to 85°C, VCC = 5.0V ± 20% (unless otherwise noted)
Symbol
Parameter
Condition
Min
Max
Units
VIL
Input Low-voltage
(Except EA)
-0.5
0.2 VCC - 0.1
V
VIL1
Input Low-voltage (EA)
-0.5
0.2 VCC - 0.3
V
VIH
Input High-voltage
0.2 VCC + 0.9
VCC + 0.5
V
VIH1
Input High-voltage
0.7 VCC
VCC + 0.5
V
IOL = 1.6 mA
0.45
V
IOL = 3.2 mA
0.45
V
VOL
Output Low-voltage
(Except XTAL1, RST)
(XTAL1, RST)
(1)
(Ports 1,2,3)
(1)
VOL1
Output Low-voltage
(Port 0, ALE, PSEN)
VOH
Output High-voltage
(Ports 1,2,3, ALE, PSEN)
IOH = -60 µA, VCC = 5V ± 10%
2.4
V
IOH = -25 µA
0.75 VCC
V
IOH = -10 µA
0.9 VCC
V
2.4
V
IOH = -300 µA
0.75 VCC
V
IOH = -80 µA
0.9 VCC
V
IOH = -800 µA, VCC = 5V ± 10%
VOH1
Output High-voltage
(Port 0 in External Bus Mode)
IIL
Logical 0 Input Current (Ports 1,2,3)
VIN = 0.45V
-50
µA
ITL
Logical 1 to 0 Transition Current
(Ports 1,2,3)
VIN = 2V, VCC = 5V ± 10%
-650
µA
ILI
Input Leakage Current (Port 0, EA)
0.45 < VIN < VCC
±10
µA
RRST
Reset Pull-down Resistor
300
KΩ
CIO
Pin Capacitance
Test Freq. = 1 MHz, TA = 25°C
10
pF
Active Mode, 12 MHz
20
mA
Idle Mode, 12 MHz
5
mA
VCC = 6V
100
µA
VCC = 3V
40
µA
50
Power Supply Current
ICC
Power-down Mode(2)
Notes:
10
1. Under steady state (non-transient) conditions, IOL must be externally limited as follows:
Maximum IOL per port pin: 10 mA
Maximum IOL per 8-bit port: Port 0: 26 mA
Ports 1, 2, 3: 15 mA
Maximum total IOL for all output pins: 71 mA
If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater
than the listed test conditions.
2. Minimum VCC for Power-down is 2V.
AT89C51
AT89C51
AC Characteristics
Under operating conditions, load capacitance for Port 0, ALE/PROG, and PSEN = 100 pF; load capacitance for all other
outputs = 80 pF.
External Program and Data Memory Characteristics
12 MHz Oscillator
Min
Max
16 to 24 MHz Oscillator
Symbol
Parameter
Min
Max
Units
1/tCLCL
0
24
MHz
tLHLL
ALE Pulse Width
127
2tCLCL-40
ns
tAVLL
Address Valid to ALE Low
43
tCLCL-13
ns
tLLAX
Address Hold after ALE Low
48
tCLCL-20
ns
tLLIV
ALE Low to Valid Instruction In
tLLPL
ALE Low to PSEN Low
43
tCLCL-13
ns
tPLPH
PSEN Pulse Width
205
3tCLCL-20
ns
tPLIV
PSEN Low to Valid Instruction In
tPXIX
Input Instruction Hold after PSEN
tPXIZ
Input Instruction Float after PSEN
tPXAV
PSEN to Address Valid
tAVIV
Address to Valid Instruction In
312
5tCLCL-55
ns
tPLAZ
PSEN Low to Address Float
10
10
ns
tRLRH
RD Pulse Width
400
6tCLCL-100
ns
tWLWH
WR Pulse Width
400
6tCLCL-100
ns
tRLDV
RD Low to Valid Data In
tRHDX
Data Hold after RD
tRHDZ
Data Float after RD
97
2tCLCL-28
ns
tLLDV
ALE Low to Valid Data In
517
8tCLCL-150
ns
tAVDV
Address to Valid Data In
585
9tCLCL-165
ns
tLLWL
ALE Low to RD or WR Low
200
3tCLCL+50
ns
tAVWL
Address to RD or WR Low
203
4tCLCL-75
ns
tQVWX
Data Valid to WR Transition
23
tCLCL-20
ns
tQVWH
Data Valid to WR High
433
7tCLCL-120
ns
tWHQX
Data Hold after WR
33
tCLCL-20
ns
tRLAZ
RD Low to Address Float
tWHLH
RD or WR High to ALE High
233
4tCLCL-65
145
0
3tCLCL-45
0
59
75
tCLCL-8
0
5tCLCL-90
3tCLCL-50
0
43
123
tCLCL-20
ns
ns
0
300
ns
ns
tCLCL-10
252
ns
ns
ns
0
ns
tCLCL+25
ns
11
External Program Memory Read Cycle
tLHLL
ALE
tAVLL
tLLIV
tLLPL
tPLIV
PSEN
tPXAV
tPLAZ
tPXIZ
tLLAX
tPXIX
A0 - A7
PORT 0
tPLPH
INSTR IN
A0 - A7
tAVIV
PORT 2
A8 - A15
A8 - A15
External Data Memory Read Cycle
tLHLL
ALE
tWHLH
PSEN
tLLDV
tRLRH
tLLWL
RD
tLLAX
tAVLL
PORT 0
tRLDV
tRLAZ
A0 - A7 FROM RI OR DPL
tRHDZ
tRHDX
DATA IN
A0 - A7 FROM PCL
INSTR IN
tAVWL
tAVDV
PORT 2
12
P2.0 - P2.7 OR A8 - A15 FROM DPH
AT89C51
A8 - A15 FROM PCH
AT89C51
External Data Memory Write Cycle
tLHLL
ALE
tWHLH
PSEN
tLLWL
WR
tAVLL
tLLAX
tQVWX
A0 - A7 FROM RI OR DPL
PORT 0
tWLWH
tQVWH
DATA OUT
tWHQX
A0 - A7 FROM PCL
INSTR IN
tAVWL
PORT 2
P2.0 - P2.7 OR A8 - A15 FROM DPH
A8 - A15 FROM PCH
External Clock Drive Waveforms
tCHCX
VCC - 0.5V
tCHCX
tCLCH
tCHCL
0.7 VCC
0.2 VCC - 0.1V
0.45V
tCLCX
tCLCL
External Clock Drive
Symbol
Parameter
1/tCLCL
tCLCL
Clock Period
tCHCX
Min
Max
Units
0
24
MHz
41.6
ns
High Time
15
ns
tCLCX
Low Time
15
ns
tCLCH
Rise Time
20
ns
tCHCL
Fall Time
20
ns
13
Serial Port Timing: Shift Register Mode Test Conditions
(VCC = 5.0 V ± 20%; Load Capacitance = 80 pF)
12 MHz Osc
Variable Oscillator
Max
Min
Units
Symbol
Parameter
Min
Max
tXLXL
Serial Port Clock Cycle Time
1.0
12tCLCL
µs
tQVXH
Output Data Setup to Clock Rising Edge
700
10tCLCL-133
ns
tXHQX
Output Data Hold after Clock Rising Edge
50
2tCLCL-117
ns
tXHDX
Input Data Hold after Clock Rising Edge
0
0
ns
tXHDV
Clock Rising Edge to Input Data Valid
700
10tCLCL-133
ns
Shift Register Mode Timing Waveforms
INSTRUCTION
ALE
0
1
2
3
4
5
6
7
8
tXLXL
CLOCK
tQVXH
WRITE TO SBUF
tXHQX
0
1
tXHDV
OUTPUT DATA
CLEAR RI
VALID
2
3
4
5
6
tXHDX
VALID
SET TI
VALID
VALID
VALID
VALID
VALID
AC Testing Input/Output Waveforms(1)
Note:
14
Float Waveforms(1)
V LOAD+
0.2 VCC + 0.9V
TEST POINTS
0.45V
VALID
SET RI
INPUT DATA
VCC - 0.5V
7
AT89C51
V LOAD -
Note:
V OL -
0.1V
V OL +
0.1V
Timing Reference
Points
V LOAD
0.2 VCC - 0.1V
1. AC Inputs during testing are driven at VCC - 0.5V for a
logic 1 and 0.45V for a logic 0. Timing measurements
are made at VIH min. for a logic 1 and VIL max. for a
logic 0.
0.1V
0.1V
1. For timing purposes, a port pin is no longer floating
when a 100 mV change from load voltage occurs. A
port pin begins to float when 100 mV change from
the loaded VOH/VOL level occurs.
AT89C51
Ordering Information
Speed
(MHz)
Power
Supply
Ordering Code
Package
12
5V ± 20%
AT89C51-12AC
44A
Commercial
AT89C51-12JC
44J
(0° C to 70° C)
AT89C51-12PC
40P6
AT89C51-12QC
44Q
AT89C51-12AI
44A
Industrial
AT89C51-12JI
44J
(-40° C to 85° C)
AT89C51-12PI
40P6
AT89C51-12QI
44Q
AT89C51-16AC
44A
Commercial
AT89C51-16JC
44J
(0° C to 70° C)
AT89C51-16PC
40P6
AT89C51-16QC
44Q
AT89C51-16AI
44A
Industrial
AT89C51-16JI
44J
(-40° C to 85° C)
AT89C51-16PI
40P6
AT89C51-16QI
44Q
AT89C51-20AC
44A
Commercial
AT89C51-20JC
44J
(0° C to 70° C)
AT89C51-20PC
40P6
AT89C51-20QC
44Q
AT89C51-20AI
44A
Industrial
AT89C51-20JI
44J
(-40° C to 85° C)
AT89C51-20PI
40P6
AT89C51-20QI
44Q
AT89C51-24AC
44A
Commercial
AT89C51-24JC
44J
(0° C to 70° C)
AT89C51-24PC
40P6
AT89C51-24QC
44Q
AT89C51-24AI
44A
Industrial
AT89C51-24JI
44J
(-40° C to 85° C)
AT89C51-24PI
40P6
AT89C51-24QI
44Q
16
20
24
5V ± 20%
5V ± 20%
5V ± 20%
Operation Range
Package Type
44A
44-lead, Thin Plastic Gull Wing Quad Flatpack (TQFP)
44J
44-lead, Plastic J-leaded Chip Carrier (PLCC)
40P6
40-lead, 0.600” Wide, Plastic Dual Inline Package (PDIP)
44Q
44-lead, Plastic Gull Wing Quad Flatpack (PQFP)
15
Packaging Information
44A, 44-lead, Thin (1.0 mm) Plastic Gull Wing Quad
Flatpack (TQFP)
Dimensions in Millimeters and (Inches)*
44J, 44-lead, Plastic J-leaded Chip Carrier (PLCC)
Dimensions in Inches and (Millimeters)
JEDEC STANDARD MS-018 AC
JEDEC STANDARD MS-026 ACB
12.21(0.478)
SQ
11.75(0.458)
PIN 1 ID
0.45(0.018)
0.30(0.012)
0.80(0.031) BSC
.045(1.14) X 45°
.045(1.14) X 30° - 45°
PIN NO. 1
IDENTIFY
.630(16.0)
.590(15.0)
.656(16.7)
SQ
.650(16.5)
.032(.813)
.026(.660)
.695(17.7)
SQ
.685(17.4)
.050(1.27) TYP
.500(12.7) REF SQ
10.10(0.394)
SQ
9.90(0.386)
.021(.533)
.013(.330)
.043(1.09)
.020(.508)
.120(3.05)
.090(2.29)
.180(4.57)
.165(4.19)
1.20(0.047) MAX
0
7
0.20(.008)
0.09(.003)
.012(.305)
.008(.203)
.022(.559) X 45° MAX (3X)
0.75(0.030)
0.45(0.018)
0.15(0.006)
0.05(0.002)
Controlling dimension: millimeters
40P6, 40-lead, 0.600" Wide, Plastic Dual Inline
Package (PDIP)
Dimensions in Inches and (Millimeters)
2.07(52.6)
2.04(51.8)
44Q, 44-lead, Plastic Quad Flat Package (PQFP)
Dimensions in Millimeters and (Inches)*
JEDEC STANDARD MS-022 AB
13.45 (0.525)
SQ
12.95 (0.506)
PIN
1
PIN 1 ID
.566(14.4)
.530(13.5)
0.50 (0.020)
0.35 (0.014)
0.80 (0.031) BSC
.090(2.29)
MAX
1.900(48.26) REF
.220(5.59)
MAX
.005(.127)
MIN
SEATING
PLANE
.065(1.65)
.015(.381)
.022(.559)
.014(.356)
.161(4.09)
.125(3.18)
.110(2.79)
.090(2.29)
.012(.305)
.008(.203)
.065(1.65)
.041(1.04)
10.10 (0.394)
SQ
9.90 (0.386)
.630(16.0)
.590(15.0)
2.45 (0.096) MAX
0 REF
15
.690(17.5)
.610(15.5)
0.17 (0.007)
0.13 (0.005)
0
7
1.03 (0.041)
0.78 (0.030)
Controlling dimension: millimeters
16
AT89C51
0.25 (0.010) MAX
Atmel Headquarters
Atmel Operations
Corporate Headquarters
Atmel Colorado Springs
2325 Orchard Parkway
San Jose, CA 95131
TEL (408) 441-0311
FAX (408) 487-2600
Europe
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Colorado Springs, CO 80906
TEL (719) 576-3300
FAX (719) 540-1759
Atmel Rousset
Atmel U.K., Ltd.
Coliseum Business Centre
Riverside Way
Camberley, Surrey GU15 3YL
England
TEL (44) 1276-686-677
FAX (44) 1276-686-697
Zone Industrielle
13106 Rousset Cedex
France
TEL (33) 4-4253-6000
FAX (33) 4-4253-6001
Asia
Atmel Asia, Ltd.
Room 1219
Chinachem Golden Plaza
77 Mody Road Tsimhatsui
East Kowloon
Hong Kong
TEL (852) 2721-9778
FAX (852) 2722-1369
Japan
Atmel Japan K.K.
9F, Tonetsu Shinkawa Bldg.
1-24-8 Shinkawa
Chuo-ku, Tokyo 104-0033
Japan
TEL (81) 3-3523-3551
FAX (81) 3-3523-7581
Fax-on-Demand
North America:
1-(800) 292-8635
International:
1-(408) 441-0732
e-mail
[email protected]
Web Site
http://www.atmel.com
BBS
1-(408) 436-4309
© Atmel Corporation 2000.
Atmel Corporation makes no warranty for the use of its products, other than those expressly contained in the Company’s standard warranty which is detailed in Atmel’s Terms and Conditions located on the Company’s web site. The Company assumes no responsibility for
any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without
notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of Atmel are granted by the Company in connection with the sale of Atmel products, expressly or by implication. Atmel’s products are
not authorized for use as critical components in life suppor t devices or systems.
Marks bearing
®
and/or
™
are registered trademarks and trademarks of Atmel Corporation.
Terms and product names in this document may be trademarks of others.
Printed on recycled paper.
0265G–02/00/xM
ANEXO A.2 – MAX233A
19-4323; Rev 11; 2/03
+5V-Powered, Multichannel RS-232
Drivers/Receivers
____________________________Features
Superior to Bipolar
♦ Operate from Single +5V Power Supply
(+5V and +12V—MAX231/MAX239)
♦ Low-Power Receive Mode in Shutdown
(MAX223/MAX242)
♦ Meet All EIA/TIA-232E and V.28 Specifications
♦ Multiple Drivers and Receivers
♦ 3-State Driver and Receiver Outputs
♦ Open-Line Detection (MAX243)
Ordering Information
________________________Applications
PART
MAX220CPE
MAX220CSE
MAX220CWE
MAX220C/D
MAX220EPE
MAX220ESE
MAX220EWE
MAX220EJE
MAX220MJE
Portable Computers
Low-Power Modems
Interface Translation
Battery-Powered RS-232 Systems
Multidrop RS-232 Networks
TEMP RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
PIN-PACKAGE
16 Plastic DIP
16 Narrow SO
16 Wide SO
Dice*
16 Plastic DIP
16 Narrow SO
16 Wide SO
16 CERDIP
16 CERDIP
Ordering Information continued at end of data sheet.
*Contact factory for dice specifications.
Selection Table
Part
Number
MAX220
MAX222
MAX223 (MAX213)
MAX225
MAX230 (MAX200)
MAX231 (MAX201)
MAX232 (MAX202)
MAX232A
MAX233 (MAX203)
MAX233A
MAX234 (MAX204)
MAX235 (MAX205)
MAX236 (MAX206)
MAX237 (MAX207)
MAX238 (MAX208)
MAX239 (MAX209)
MAX240
MAX241 (MAX211)
MAX242
MAX243
MAX244
MAX245
MAX246
MAX247
MAX248
MAX249
Power
Supply
(V)
+5
+5
+5
+5
+5
+5 and
+7.5 to +13.2
+5
+5
+5
+5
+5
+5
+5
+5
+5
+5 and
+7.5 to +13.2
+5
+5
+5
+5
+5
+5
+5
+5
+5
+5
No. of
RS-232
Drivers/Rx
2/2
2/2
4/5
5/5
5/0
2/2
No. of
Ext. Caps
4
4
4
0
4
2
Nominal
Cap. Value
(µF)
0.1
0.1
1.0 (0.1)
—
1.0 (0.1)
1.0 (0.1)
SHDN
& ThreeState
No
Yes
Yes
Yes
Yes
No
Rx
Active in
SHDN
—
—
✔
✔
—
—
Data Rate
(kbps)
120
200
120
120
120
120
2/2
2/2
2/2
2/2
4/0
5/5
4/3
5/3
4/4
3/5
4
4
0
0
4
0
4
4
4
2
1.0 (0.1)
0.1
—
—
1.0 (0.1)
—
1.0 (0.1)
1.0 (0.1)
1.0 (0.1)
1.0 (0.1)
No
No
No
No
No
Yes
Yes
No
No
No
—
—
—
—
—
—
—
—
—
—
120 (64)
200
120
200
120
120
120
120
120
120
5/5
4/5
2/2
2/2
8/10
8/10
8/10
8/9
8/8
6/10
4
4
4
4
4
0
0
0
4
4
1.0
1.0 (0.1)
0.1
0.1
1.0
—
—
—
1.0
1.0
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
Yes
—
—
✔
—
—
✔
✔
✔
✔
✔
120
120
200
200
120
120
120
120
120
120
Features
Ultra-low-power, industry-standard pinout
Low-power shutdown
MAX241 and receivers active in shutdown
Available in SO
5 drivers with shutdown
Standard +5/+12V or battery supplies;
same functions as MAX232
Industry standard
Higher slew rate, small caps
No external caps
No external caps, high slew rate
Replaces 1488
No external caps
Shutdown, three state
Complements IBM PC serial port
Replaces 1488 and 1489
Standard +5/+12V or battery supplies;
single-package solution for IBM PC serial port
DIP or flatpack package
Complete IBM PC serial port
Separate shutdown and enable
Open-line detection simplifies cabling
High slew rate
High slew rate, int. caps, two shutdown modes
High slew rate, int. caps, three shutdown modes
High slew rate, int. caps, nine operating modes
High slew rate, selective half-chip enables
Available in quad flatpack package
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX220–MAX249
General Description
The MAX220–MAX249 family of line drivers/receivers is
intended for all EIA/TIA-232E and V.28/V.24 communications interfaces, particularly applications where ±12V is
not available.
These parts are especially useful in battery-powered systems, since their low-power shutdown mode reduces
power dissipation to less than 5µW. The MAX225,
MAX233, MAX235, and MAX245/MAX246/MAX247 use
no external components and are recommended for applications where printed circuit board space is critical.
MAX220–MAX249
Drivers/Receivers
ABSOLUTE MAXIMUM RATINGS—MAX220/222/232A/233A/242/243
20-Pin Plastic DIP (derate 8.00mW/°C above +70°C) ..440mW
16-Pin Narrow SO (derate 8.70mW/°C above +70°C) ...696mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C)......762mW
18-Pin Wide SO (derate 9.52mW/°C above +70°C)......762mW
20-Pin Wide SO (derate 10.00mW/°C above +70°C)....800mW
20-Pin SSOP (derate 8.00mW/°C above +70°C) ..........640mW
16-Pin CERDIP (derate 10.00mW/°C above +70°C).....800mW
18-Pin CERDIP (derate 10.53mW/°C above +70°C).....842mW
Operating Temperature Ranges
MAX2_ _AC_ _, MAX2_ _C_ _ .............................0°C to +70°C
MAX2_ _AE_ _, MAX2_ _E_ _ ..........................-40°C to +85°C
MAX2_ _AM_ _, MAX2_ _M_ _ .......................-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Supply Voltage (VCC) ...............................................-0.3V to +6V
Input Voltages
TIN..............................................................-0.3V to (VCC - 0.3V)
RIN (Except MAX220) ........................................................±30V
RIN (MAX220).....................................................................±25V
TOUT (Except MAX220) (Note 1) .......................................±15V
TOUT (MAX220)...............................................................±13.2V
Output Voltages
TOUT ...................................................................................±15V
ROUT .........................................................-0.3V to (VCC + 0.3V)
Driver/Receiver Output Short Circuited to GND.........Continuous
Continuous Power Dissipation (TA = +70°C)
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)....842mW
Note 1: Input voltage measured with TOUT in high-impedance state, SHDN or VCC = 0V.
Note 2: For the MAX220, V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS—MAX220/222/232A/233A/242/243
(VCC = +5V ±10%, C1–C4 = 0.1µF‚ MAX220, C1 = 0.047µF, C2–C4 = 0.33µF, TA = TMIN to TMAX‚ unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
RS-232 TRANSMITTERS
Output Voltage Swing
All transmitter outputs loaded with 3kΩ to GND
±5
Input Logic Threshold Low
Input Logic Threshold High
Logic Pull-Up/lnput Current
Output Leakage Current
±8
1.4
All devices except MAX220
MAX220: VCC = 5.0V
2
V
0.8
1.4
V
2.4
All except MAX220, normal operation
5
40
SHDN = 0V, MAX222/242, shutdown, MAX220
±0.01
±1
VCC = 5.5V, SHDN = 0V, VOUT = ±15V, MAX222/242
±0.01
±10
VCC = SHDN = 0V, VOUT = ±15V
±0.01
±10
200
116
Data Rate
V
µA
µA
kbps
Transmitter Output Resistance
VCC = V+ = V- = 0V, VOUT = ±2V
300
10M
Ω
Output Short-Circuit Current
VOUT = 0V
±7
±22
mA
RS-232 RECEIVERS
RS-232 Input Voltage Operating Range
±30
RS-232 Input Threshold Low
VCC = 5V
RS-232 Input Threshold High
VCC = 5V
RS-232 Input Hysteresis
All except MAX243 R2IN
0.8
MAX243 R2IN (Note 2)
-3
1.8
2.4
MAX243 R2IN (Note 2)
-0.5
-0.1
0.5
1
RS-232 Input Resistance
2
1
3
TTL/CMOS Output Voltage High
IOUT = -1.0mA
TTL/CMOS Output Short-Circuit Current
0.2
MAX243
IOUT = 3.2mA
V
All except MAX243 R2IN
All except MAX243, VCC = 5V, no hysteresis in shdn.
TTL/CMOS Output Voltage Low
1.3
V
V
V
5
7
kΩ
0.2
0.4
V
3.5
VCC - 0.2
Sourcing VOUT = GND
-2
-10
Shrinking VOUT = VCC
10
30
_______________________________________________________________________________________
V
mA
Drivers/Receivers
(VCC = +5V ±10%, C1–C4 = 0.1µF‚ MAX220, C1 = 0.047µF, C2–C4 = 0.33µF, TA = TMIN to TMAX‚ unless otherwise noted.)
PARAMETER
CONDITIONS
TTL/CMOS Output Leakage Current
SHDN = VCC or EN = VCC (SHDN = 0V for MAX222),
0V ≤ VOUT ≤ VCC
EN Input Threshold Low
MAX242
EN Input Threshold High
MAX242
2.0
Operating Supply Voltage
3kΩ load
both inputs
MAX220
UNITS
±0.05
±10
µA
1.4
0.8
V
1.4
5.5
MAX222/232A/233A/242/243
4
10
MAX220
12
MAX222/232A/233A/242/243
15
TA = +25°C
0.1
10
TA = 0°C to +70°C
2
50
TA = -40°C to +85°C
2
50
TA = -55°C to +125°C
35
100
SHDN Input Leakage Current
MAX222/242
SHDN Threshold Low
MAX222/242
SHDN Threshold High
MAX222/242
CL = 50pF to 2500pF,
MAX222/232A/233A/242/243
RL = 3kΩ to 7kΩ,
VCC = 5V, TA = +25°C,
measured from +3V MAX220
to -3V or -3V to +3V
MAX222/232A/233A/242/243
tPHLT
MAX220
tPLHT
V
2
MAX222/242
Transmitter Propagation Delay
TLL to RS-232 (Normal Operation),
Figure 1
MAX
0.5
Shutdown Supply Current
Transition Slew Rate
TYP
4.5
No load
VCC Supply Current (SHDN = VCC),
Figures 5, 6, 11, 19
MIN
1.4
MAX222/232A/233A/242/243
mA
µA
±1
µA
0.8
V
2.0
1.4
V
6
12
30
1.5
3
30
1.3
3.5
V/µs
4
10
1.5
3.5
µs
5
10
MAX222/232A/233A/242/243
0.5
1
MAX220
0.6
3
MAX222/232A/233A/242/243
0.6
1
MAX220
0.8
3
tPHLS
MAX242
0.5
10
tPLHS
MAX242
2.5
10
Receiver-Output Enable Time, Figure 3 tER
MAX242
125
500
ns
Receiver-Output Disable Time, Figure 3 tDR
MAX242
160
500
ns
Transmitter-Output Enable Time
(SHDN Goes High), Figure 4
tET
MAX222/242, 0.1µF caps
(includes charge-pump start-up)
250
µs
Transmitter-Output Disable Time
(SHDN Goes Low), Figure 4
tDT
MAX222/242, 0.1µF caps
600
ns
Transmitter + to - Propagation
Delay Difference (Normal Operation)
tPHLT - tPLHT
MAX222/232A/233A/242/243
300
MAX220
2000
Receiver + to - Propagation
tPHLR - tPLHR
MAX222/232A/233A/242/243
100
MAX220
225
Receiver Propagation Delay
RS-232 to TLL (Normal Operation),
Figure 2
RS-232 to TLL (Shutdown), Figure 2
tPHLR
tPLHR
MAX220
V
µs
µs
ns
ns
Note 3: MAX243 R2OUT is guaranteed to be low when R2IN is ≥ 0V or is floating.
_______________________________________________________________________________________
3
MAX220–MAX249
ELECTRICAL CHARACTERISTICS—MAX220/222/232A/233A/242/243 (continued)
__________________________________________Typical Operating Characteristics
MAX220/MAX222/MAX232A/MAX233A/MAX242/MAX243
VCC = ±5V
NO LOAD ON
TRANSMITTER OUTPUTS
(EXCEPT MAX220, MAX233A)
2
0
0.1µF
V- LOADED, NO LOAD ON V+
-2
1µF
0.1µF
-4
ALL CAPS
1µF
9
VCC = +5.25V
8
ALL CAPS
0.1µF
7
1µF CAPS
V+
V+, V- VOLTAGE (V)
EITHER V+ OR V- LOADED
4
+10V
MAX220-02
6
OUTPUT LOAD CURRENT
FLOWS FROM V+ TO V-
10
OUTPUT CURRENT (mA)
1µF
8
11
MAX220-01
10
MAX222/MAX242
ON-TIME EXITING SHUTDOWN
VCC = +4.75V
+5V
+5V
V+
0.1µF CAPS
SHDN
0V
0V
1µF CAPS
6
-6
V+ LOADED, NO LOAD ON V-
-10
0
5
10
15
LOAD CURRENT (mA)
4
0.1µF CAPS
5
-8
20
25
V-
V-
-10V
4
0
10
20
30
40
50
60
500µs/div
DATA RATE (kbits/sec)
_______________________________________________________________________________________
MAX220-03
AVAILABLE OUTPUT CURRENT
vs. DATA RATE
OUTPUT VOLTAGE vs. LOAD CURRENT
OUTPUT VOLTAGE (V)
MAX220–MAX249
Drivers/Receivers
Drivers/Receivers
20-Pin Wide SO (derate 10 00mW/°C above +70°C).......800mW
24-Pin Wide SO (derate 11.76mW/°C above +70°C).......941mW
28-Pin Wide SO (derate 12.50mW/°C above +70°C) .............1W
44-Pin Plastic FP (derate 11.11mW/°C above +70°C) .....889mW
14-Pin CERDIP (derate 9.09mW/°C above +70°C) ..........727mW
16-Pin CERDIP (derate 10.00mW/°C above +70°C) ........800mW
20-Pin CERDIP (derate 11.11mW/°C above +70°C) ........889mW
24-Pin Narrow CERDIP
(derate 12.50mW/°C above +70°C) ..............1W
24-Pin Sidebraze (derate 20.0mW/°C above +70°C)..........1.6W
28-Pin SSOP (derate 9.52mW/°C above +70°C).............762mW
MAX2 _ _ C _ _......................................................0°C to +70°C
MAX2 _ _ E _ _ ...................................................-40°C to +85°C
MAX2 _ _ M _ _ ...............................................-55°C to +125°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS—MAX223/MAX230–MAX241
(MAX223/230/232/234/236/237/238/240/241, VCC = +5V ±10; MAX233/MAX235, VCC = 5V ±5%‚ C1–C4 = 1.0µF; MAX231/MAX239,
VCC = 5V ±10%; V+ = 7.5V to 13.2V; TA = TMIN to TMAX; unless otherwise noted.)
PARAMETER
CONDITIONS
All transmitter outputs loaded with 3kΩ to ground
MIN
TYP
±5.0
±7.3
MAX232/233
VCC Power-Supply Current
No load,
TA = +25°C
V+ Power-Supply Current
MAX223/230/234–238/240/241
10
7
15
0.4
1
MAX231
1.8
5
MAX239
5
15
MAX223
15
50
MAX230/235/236/240/241
1
10
TA = +25°C
TIN; EN, SHDN (MAX233); EN, SHDN (MAX230/235–241)
0.8
TIN
2.0
EN, SHDN (MAX223);
EN, SHDN (MAX230/235/236/240/241)
2.4
Logic Pull-Up Current
TIN = 0V
mA
mA
µA
V
V
1.5
-30
UNITS
V
5
MAX231/239
Receiver Input Voltage
Operating Range
MAX
200
µA
30
V
_______________________________________________________________________________________
5
MAX220–MAX249
ABSOLUTE MAXIMUM RATINGS—MAX223/MAX230–MAX241
VCC ...........................................................................-0.3V to +6V
V+ ................................................................(VCC - 0.3V) to +14V
V- ............................................................................+0.3V to -14V
Input Voltages
TIN ............................................................-0.3V to (VCC + 0.3V)
RIN......................................................................................±30V
Output Voltages
TOUT ...................................................(V+ + 0.3V) to (V- - 0.3V)
ROUT .........................................................-0.3V to (VCC + 0.3V)
Short-Circuit Duration, TOUT ......................................Continuous
24-Pin Narrow Plastic DIP
(derate 13.33mW/°C above +70°C) ..........1.07W
24-Pin Plastic DIP (derate 9.09mW/°C above +70°C)......500mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C).........762mW
MAX220–MAX249
Drivers/Receivers
ELECTRICAL CHARACTERISTICS—MAX223/MAX230–MAX241 (continued)
(MAX223/230/232/234/236/237/238/240/241, VCC = +5V ±10; MAX233/MAX235, VCC = 5V ±5%‚ C1–C4 = 1.0µF; MAX231/MAX239,
VCC = 5V ±10%; V+ = 7.5V to 13.2V; TA = TMIN to TMAX; unless otherwise noted.)
PARAMETER
CONDITIONS
TA = +25°C,
VCC = 5V
TA = +25°C,
VCC = 5V
Normal operation
SHDN = 5V (MAX223)
SHDN = 0V (MAX235/236/240/241)
MIN
TYP
0.8
1.2
0.6
Normal operation
SHDN = 5V (MAX223)
SHDN = 0V (MAX235/236/240/241)
1.5
1.7
1.5
2.4
0.2
0.5
1.0
V
3
5
7
kΩ
0.4
V
3.5
VCC - 0.4
TA = +25°C, VCC = 5V
IOUT = 1.6mA (MAX231/232/233, IOUT = 3.2mA)
IOUT = -1mA
0V ≤ ROUT ≤ VCC; EN = 0V (MAX223);
EN = VCC (MAX235–241 )
Receiver Output Enable Time
Normal
operation
MAX223
600
MAX235/236/239/240/241
400
Receiver Output Disable Time
Normal
operation
MAX223
900
MAX235/236/239/240/241
250
Propagation Delay
Normal operation
RS-232 IN to
TTL/CMOS OUT, SHDN = 0V
CL = 150pF
(MAX223)
Transmitter Output Short-Circuit
Current
6
2.4
V
Shutdown (MAX223)
SHDN = 0V,
EN = 5V (R4IN‚ R5IN)
VCC = 5V, no hysteresis in shutdown
UNITS
V
Shutdown (MAX223)
SHDN = 0V,
EN = 5V (R4IN, R5IN)
Transition Region Slew Rate
MAX
0.05
±10
ns
0.5
10
4
40
tPLHS
6
40
5.1
30
3
µA
ns
tPHLS
MAX223/MAX230/MAX234–241, TA = +25°C, VCC = 5V,
RL = 3kΩ to 7kΩ‚ CL = 50pF to 2500pF, measured from
+3V to -3V or -3V to +3V
µs
V/µs
MAX231/MAX232/MAX233, TA = +25°C, VCC = 5V,
RL = 3kΩ to 7kΩ, CL = 50pF to 2500pF, measured from
+3V to -3V or -3V to +3V
VCC = V+ = V- = 0V, VOUT = ±2V
V
4
30
Ω
300
±10
_______________________________________________________________________________________
mA
mA
Drivers/Receivers
TRANSMITTER OUTPUT VOLTAGE (VOH)
vs. LOAD CAPACITANCE AT
DIFFERENT DATA RATES
2 TRANSMITTERS
LOADED
7.2
7.0
6.5
4.5
6.6
TA = +25°C
VCC = +5V
3 TRANSMITTERS LOADED
RL = 3kΩ
C1–C4 = 1µF
6.4
6.2
6.0
0
500
1000
1500
8.0
7.0
3 TRANSMITTERS
LOADED
4 TRANSMITTERS
LOADED
6.0
5.0
4.0
0
2500
2000
500
1000
1500
2000
2500
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT
VOLTAGE (VOL) vs. VCC
TRANSMITTER OUTPUT VOLTAGE (VOL)
TRANSMITTER OUTPUT VOLTAGE (V+, V-)
vs. LOAD CURRENT
TA = +25°C
VCC = +5V
3 TRANSMITTERS LOADED
RL = 3kΩ
C1–C4 = 1µF
-6.2
-6.4
VOL (V)
-6.6
-7.5
1 TRANSMITTER
LOADED
2 TRANSMITTERS
LOADED
10
8
6
-7.0
TA = +25°C
VCC = +5V
C1–C4 = 1µF
V- LOADED,
V+ AND VNO LOAD
EQUALLY
ON V+
LOADED
4
160kbits/sec
80kbits/sec
20Kkbits/sec
-6.8
MAX220-09
-6.0
MAX220-08
TA = +25°C
C1–C4 = 1µF
TRANSMITTER
LOADS =
3kΩ || 2500pF
2
V+, V- (V)
-7.0
0
-2
V+ LOADED,
NO LOAD
ON V-
-4
-7.2
3 TRANSMITTERS
LOADED
-6
-7.4
-8
5.0
VCC (V)
5.5
ALL TRANSMITTERS UNLOADED
-10
-7.6
-9.0
4.5
2 TRANSMITTERS
LOADED
9.0
4 TRANSMITTERS
LOADED
-8.5
SLEW RATE (V/µs)
160kbits/sec
80kbits/sec
20kbits/sec
VCC (V)
-6.5
-8.0
TA = +25°C
VCC = +5V
LOADED, RL = 3kΩ
C1–C4 = 1µF
10.0
6.8
5.5
5.0
-6.0
VOL (V)
VOH (V)
3 TRANSMITTERS
LOADED
TA = +25°C
C1–C4 = 1µF
TRANSMITTER
4 TRANSMITTERS LOADS =
3kΩ || 2500pF
LOADED
7.5
1 TRANSMITTER LOADED
11.0
7.0
1 TRANSMITTER
LOADED
MAX220-07
VOH (V)
8.0
12.0
MAX220-05
7.4
MAX220-04
8.5
TRANSMITTER SLEW RATE
vs. LOAD CAPACITANCE
MAX220-06
TRANSMITTER OUTPUT
VOLTAGE (VOH) vs. VCC
0
500
1000
1500
0
2500
2000
5
10 15 20 25 30 35 40 45 50
CURRENT (mA)
V+, V- WHEN EXITING SHUTDOWN
(1µF CAPACITORS)
MAX220-13
V+
O
V-
SHDN*
500ms/div
*SHUTDOWN POLARITY IS REVERSED
FOR NON MAX241 PARTS
_______________________________________________________________________________________
7
MAX220–MAX249
MAX223/MAX230–MAX241
MAX220–MAX249
Drivers/Receivers
ABSOLUTE MAXIMUM RATINGS—MAX225/MAX244–MAX249
Supply Voltage (VCC) ...............................................-0.3V to +6V
Input Voltages
TIN‚ ENA, ENB, ENR, ENT, ENRA,
ENRB, ENTA, ENTB..................................-0.3V to (VCC + 0.3V)
RIN .....................................................................................±25V
TOUT (Note 3).....................................................................±15V
ROUT ........................................................-0.3V to (VCC + 0.3V)
Short Circuit (one output at a time)
TOUT to GND ............................................................Continuous
ROUT to GND............................................................Continuous
28-Pin Wide SO (derate 12.50mW/°C above +70°C) .............1W
40-Pin Plastic DIP (derate 11.11mW/°C above +70°C) ...611mW
44-Pin PLCC (derate 13.33mW/°C above +70°C) ...........1.07W
MAX225C_ _, MAX24_C_ _ ..................................0°C to +70°C
MAX225E_ _, MAX24_E_ _ ...............................-40°C to +85°C
Lead Temperature (soldering,10s) ..................................+300°C
Note 4: Input voltage measured with transmitter output in a high-impedance state, shutdown, or VCC = 0V.
ELECTRICAL CHARACTERISTICS—MAX225/MAX244–MAX249
(MAX225, VCC = 5.0V ±5%; MAX244–MAX249, VCC = +5.0V ±10%, external capacitors C1–C4 = 1µF; TA = TMIN to TMAX; unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
1.4
0.8
V
2
1.4
RS-232 TRANSMITTERS
Normal operation
Logic Pull-Up/lnput Current
Tables 1a–1d
Data Rate
Tables 1a–1d, normal operation
All transmitter outputs loaded with 3kΩ to GND
Output Leakage Current (Shutdown)
Tables 1a–1d
Shutdown
±5
V
10
50
±0.01
±1
120
64
±7.5
µA
kbps
V
ENA, ENB, ENT, ENTA, ENTB =
VCC, VOUT = ±15V
±0.01
±25
VCC = 0V,
VOUT = ±15V
±0.01
±25
µA
VCC = V+ = V- = 0V, VOUT = ±2V (Note 4)
300
10M
Ω
Output Short-Circuit Current
VOUT = 0V
±7
±30
mA
RS-232 RECEIVERS
RS-232 Input Voltage Operating Range
±25
VCC = 5V
VCC = 5V
VCC = 5V
1.3
2.4
0.2
0.5
1.0
V
3
5
7
kΩ
0.2
0.4
V
IOUT = 3.2mA
IOUT = -1.0mA
3.5
VCC - 0.2
Sourcing VOUT = GND
-2
-10
Shrinking VOUT = VCC
10
30
Normal operation, outputs disabled,
Tables 1a–1d, 0V ≤ VOUT ≤ VCC, ENR_ = VCC
V
1.8
TTL/CMOS Output Short-Circuit Current
8
0.8
V
±0.05
_______________________________________________________________________________________
V
V
mA
±0.10
µA
Drivers/Receivers
(MAX225, VCC = 5.0V ±5%; MAX244–MAX249, VCC = +5.0V ±10%, external capacitors C1–C4 = 1µF; TA = TMIN to TMAX; unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLY AND CONTROL LOGIC
Operating Supply Voltage
No load
VCC Supply Current
(Normal Operation)
3kΩ loads on
all outputs
MAX225
4.75
5.25
MAX244–MAX249
4.5
5.5
MAX225
10
20
MAX244–MAX249
11
30
MAX225
40
MAX244–MAX249
57
TA = +25°C
8
TA = TMIN to TMAX
50
Leakage current
Control Input
25
±1
Threshold low
1.4
Threshold high
0.8
2.4
1.4
5
10
30
V
mA
µA
µA
V
AC CHARACTERISTICS
Transition Slew Rate
CL = 50pF to 2500pF, RL = 3kΩ to 7kΩ, VCC = 5V,
TA = +25°C, measured from +3V to -3V or -3V to +3V
V/µs
Transmitter Propagation Delay
Figure 1
tPHLT
1.3
3.5
tPLHT
1.5
3.5
Figure 2
tPHLR
0.6
1.5
tPLHR
0.6
1.5
TLL to RS-232 (Low-Power Mode),
Figure 2
tPHLS
0.6
10
tPLHS
3.0
10
Transmitter + to - Propagation
tPHLT - tPLHT
350
ns
Receiver + to - Propagation
tPHLR - tPLHR
350
ns
µs
µs
µs
Receiver-Output Enable Time, Figure 3 tER
100
500
ns
Receiver-Output Disable Time, Figure 3 tDR
100
500
ns
Transmitter Enable Time
Transmitter Disable Time, Figure 4
tET
tDT
MAX246–MAX249
(excludes charge-pump startup)
5
µs
(includes charge-pump startup)
10
ms
100
ns
Note 5: The 300Ω minimum specification complies with EIA/TIA-232E, but the actual resistance when in shutdown mode or VCC =
0V is 10MΩ as is implied by the leakage specification.
_______________________________________________________________________________________
9
MAX220–MAX249
ELECTRICAL CHARACTERISTICS—MAX225/MAX244–MAX249 (continued)
8
V+ AND V- LOADED
EXTERNAL POWER SUPPLY
1µF CAPACITORS
12
10
40kb/s DATA RATE
8 TRANSMITTERS
LOADED WITH 3kΩ
8
6
4
VCC = 5V
EXTERNAL CHARGE PUMP
1µF CAPACITORS
8 TRANSMITTERS
DRIVING 5kΩ AND
2000pF AT 20kbits/sec
2
0
-2
EITHER V+ OR
V- LOADED
2
3
LOAD CAPACITANCE (nF)
4
5
40kb/sec
7.0
60kb/sec
6.0
V+ AND V- LOADED
100kb/sec
200kb/sec
5.5
-8
1
20kb/sec
7.5
V- LOADED
V+ LOADED
-10
0
8.0
6.5
-4
-6
2
VCC = 5V WITH ALL TRANSMITTERS DRIVEN
LOADED WITH 5kΩ
10kb/sec
8.5
V+, V (V)
OUTPUT VOLTAGE (V)
6
14
9.0
MAX220-11
VCC = 5V
4
10
10
MAX220-10
18
16
TRANSMITTER OUTPUT VOLTAGE (V+, V-)
OUTPUT VOLTAGE
vs. LOAD CURRENT FOR V+ AND V-
MAX220-12
TRANSMITTER SLEW RATE
vs. LOAD CAPACITANCE
TRANSMITTER SLEW RATE (V/µs)
MAX220–MAX249
Drivers/Receivers
ALL CAPACITIORS 1µF
5.0
0
5
10
15
20
25
LOAD CURRENT (mA)
30
35
0
1
2
3
LOAD CAPACITANCE (nF)
______________________________________________________________________________________
4
5
Drivers/Receivers
MAX220–MAX249
+3V
0V*
+3V
50%
50%
50%
50%
INPUT
INPUT
0V
VCC
OUTPUT
V+
0V
V-
OUTPUT
GND
tPLHR
tPLHS
tPHLR
tPHLS
tPHLT
tPLHT
*EXCEPT FOR R2 ON THE MAX243
WHERE -3V IS USED.
Figure 1. Transmitter Propagation-Delay Timing
Figure 2. Receiver Propagation-Delay Timing
EN
RX OUT
RX IN
1kΩ
RX
VCC - 2V
SHDN
+3V
a) TEST CIRCUIT
0V
150pF
EN INPUT
OUTPUT DISABLE TIME (tDT)
+3V
0V
V+
+5V
EN
OUTPUT ENABLE TIME (tER)
0V
-5V
+3.5V
V-
RECEIVER
OUTPUTS
+0.8V
a) TIMING DIAGRAM
b) ENABLE TIMING
+3V
EN INPUT
EN
0V
1 OR 0
TX
OUTPUT DISABLE TIME (tDR)
VOH
RECEIVER
OUTPUTS
VOL
3kΩ
50pF
VOH - 0.5V
VCC - 2V
VOL + 0.5V
b) TEST CIRCUIT
c) DISABLE TIMING
Figure 3. Receiver-Output Enable and Disable Timing
Figure 4. Transmitter-Output Disable Timing
______________________________________________________________________________________
11
MAX220–MAX249
Drivers/Receivers
Table 1a. MAX245 Control Pin Configurations
ENT
ENR
0
0
Normal Operation
0
1
1
0
1
1
OPERATION STATUS
TRANSMITTERS
RECEIVERS
All Active
All Active
Normal Operation
All Active
All 3-State
Shutdown
All 3-State
All Low-Power Receive Mode
Shutdown
All 3-State
All 3-State
Table 1b. MAX245 Control Pin Configurations
TRANSMITTERS
RECEIVERS
OPERATION
STATUS
TA1–TA4
TB1–TB4
0
Normal Operation
All Active
All Active
All Active
All Active
0
1
Normal Operation
All Active
All Active
RA1–RA4 3-State,
RA5 Active
RB1–RB4 3-State,
RB5 Active
1
0
Shutdown
All 3-State
All 3-State
All Low-Power
Receive Mode
All Low-Power
Receive Mode
1
1
Shutdown
All 3-State
All 3-State
RA1–RA4 3-State,
RA5 Low-Power
Receive Mode
RB1–RB4 3-State,
RB5 Low-Power
Receive Mode
ENT
ENR
0
RA1–RA5
RB1–RB5
Table 1c. MAX246 Control Pin Configurations
12
ENA
ENB
0
0
0
OPERATION
STATUS
TRANSMITTERS
RECEIVERS
TA1–TA4
TB1–TB4
RA1–RA5
Normal Operation
All Active
All Active
All Active
All Active
1
Normal Operation
All Active
All 3-State
All Active
RB1–RB4 3-State,
RB5 Active
1
0
Shutdown
All 3-State
All Active
RA1–RA4 3-State,
RA5 Active
All Active
1
1
Shutdown
All 3-State
All 3-State
RA1–RA4 3-State,
RA5 Low-Power
Receive Mode
RB1–RB4 3-State,
RA5 Low-Power
Receive Mode
______________________________________________________________________________________
RB1–RB5
Drivers/Receivers
TRANSMITTERS
ENTA ENTB ENRA ENRB
OPERATION
STATUS
RECEIVERS
MAX247
TA1–TA4
TB1–TB4
RA1–RA4
RB1–RB5
MAX248
TA1–TA4
TB1–TB4
RA1–RA4
RB1–RB4
TA1–TA3
TB1–TB3
0
0
0
0
Normal Operation
MAX249
All Active
All Active
All Active
RA1–RA5
All Active
RB1–RB5
0
0
0
1
Normal Operation
All Active
All Active
All Active
All 3-State, except
RB5 stays active on
MAX247
0
0
1
0
Normal Operation
All Active
All Active
All 3-State
All Active
0
0
1
1
Normal Operation
All Active
All Active
All 3-State
All 3-State, except
RB5 stays active on
MAX247
0
1
0
0
Normal Operation
All Active
All 3-State
All Active
All Active
0
1
0
1
Normal Operation
All Active
All 3-State
All Active
All 3-State, except
RB5 stays active on
MAX247
0
1
1
0
Normal Operation
All Active
All 3-State
All 3-State
All Active
0
1
1
1
Normal Operation
All Active
All 3-State
All 3-State
All 3-State, except
RB5 stays active on
MAX247
1
0
0
0
Normal Operation
All 3-State
All Active
All Active
All Active
1
0
0
1
Normal Operation
All 3-State
All Active
All Active
All 3-State, except
RB5 stays active on
MAX247
1
0
1
0
Normal Operation
All 3-State
All Active
All 3-State
All Active
1
0
1
1
Normal Operation
All 3-State
All Active
All 3-State
All 3-State, except
RB5 stays active on
MAX247
1
1
0
0
Shutdown
All 3-State
All 3-State
Low-Power
Receive Mode
Low-Power
Receive Mode
1
1
0
1
Shutdown
All 3-State
All 3-State
Low-Power
Receive Mode
All 3-State, except
RB5 stays active on
MAX247
1
1
1
0
Shutdown
All 3-State
All 3-State
All 3-State
Low-Power
Receive Mode
1
1
1
1
Shutdown
All 3-State
All 3-State
All 3-State
All 3-State, except
RB5 stays active on
MAX247
______________________________________________________________________________________
13
MAX220–MAX249
Table 1d. MAX247/MAX248/MAX249 Control Pin Configurations
MAX220–MAX249
Drivers/Receivers
_______________Detailed Description
The MAX220–MAX249 contain four sections: dual
charge-pump DC-DC voltage converters, RS-232 drivers, RS-232 receivers, and receiver and transmitter
enable control inputs.
Dual Charge-Pump Voltage Converter
The MAX220–MAX249 have two internal charge-pumps
that convert +5V to ±10V (unloaded) for RS-232 driver
operation. The first converter uses capacitor C1 to double the +5V input to +10V on C3 at the V+ output. The
second converter uses capacitor C2 to invert +10V to
-10V on C4 at the V- output.
A small amount of power may be drawn from the +10V
(V+) and -10V (V-) outputs to power external circuitry
(see the Typical Operating Characteristics section),
except on the MAX225 and MAX245–MAX247, where
these pins are not available. V+ and V- are not regulated,
so the output voltage drops with increasing load current.
Do not load V+ and V- to a point that violates the minimum ±5V EIA/TIA-232E driver output voltage when
sourcing current from V+ and V- to external circuitry.
When using the shutdown feature in the MAX222,
MAX225, MAX230, MAX235, MAX236, MAX240,
MAX241, and MAX245–MAX249, avoid using V+ and Vto power external circuitry. When these parts are shut
down, V- falls to 0V, and V+ falls to +5V. For applications where a +10V external supply is applied to the V+
pin (instead of using the internal charge pump to generate +10V), the C1 capacitor must not be installed and
the SHDN pin must be tied to VCC. This is because V+
is internally connected to VCC in shutdown mode.
RS-232 Drivers
The typical driver output voltage swing is ±8V when
loaded with a nominal 5kΩ RS-232 receiver and VCC =
+5V. Output swing is guaranteed to meet the EIA/TIA232E and V.28 specification, which calls for ±5V minimum driver output levels under worst-case conditions.
These include a minimum 3kΩ load, VCC = +4.5V, and
maximum operating temperature. Unloaded driver output voltage ranges from (V+ -1.3V) to (V- +0.5V).
Input thresholds are both TTL and CMOS compatible.
The inputs of unused drivers can be left unconnected
since 400kΩ input pull-up resistors to VCC are built in
(except for the MAX220). The pull-up resistors force the
outputs of unused drivers low because all drivers invert.
The internal input pull-up resistors typically source 12µA,
except in shutdown mode where the pull-ups are disabled. Driver outputs turn off and enter a high-impedance state—where leakage current is typically
microamperes (maximum 25µA)—when in shutdown
14
mode, in three-state mode, or when device power is
removed. Outputs can be driven to ±15V. The powersupply current typically drops to 8µA in shutdown mode.
The MAX220 does not have pull-up resistors to force the
outputs of the unused drivers low. Connect unused
inputs to GND or VCC.
The MAX239 has a receiver three-state control line, and
the MAX223, MAX225, MAX235, MAX236, MAX240,
and MAX241 have both a receiver three-state control
line and a low-power shutdown control. Table 2 shows
the effects of the shutdown control and receiver threestate control on the receiver outputs.
The receiver TTL/CMOS outputs are in a high-impedance, three-state mode whenever the three-state enable
line is high (for the MAX225/MAX235/MAX236/MAX239–
MAX241), and are also high-impedance whenever the
shutdown control line is high.
When in low-power shutdown mode, the driver outputs
are turned off and their leakage current is less than 1µA
with the driver output pulled to ground. The driver output
leakage remains less than 1µA, even if the transmitter
output is backdriven between 0V and (VCC + 6V). Below
-0.5V, the transmitter is diode clamped to ground with
1kΩ series impedance. The transmitter is also zener
clamped to approximately V CC + 6V, with a series
impedance of 1kΩ.
The driver output slew rate is limited to less than 30V/µs
as required by the EIA/TIA-232E and V.28 specifications. Typical slew rates are 24V/µs unloaded and
10V/µs loaded with 3Ω and 2500pF.
RS-232 Receivers
EIA/TIA-232E and V.28 specifications define a voltage
level greater than 3V as a logic 0, so all receivers invert.
Input thresholds are set at 0.8V and 2.4V, so receivers
respond to TTL level inputs as well as EIA/TIA-232E and
V.28 levels.
The receiver inputs withstand an input overvoltage up
to ±25V and provide input terminating resistors with
Table 2. Three-State Control of Receivers
PART
SHDN SHDN
EN(R)
RECEIVERS
X
Low
High
EN
__
High Impedance
Active
High Impedance
MAX223
__
Low
High
High
MAX225
__
__
__
Low
High
High Impedance
Active
MAX235
MAX236
MAX240
Low
Low
High
__
__
Low
High
X
High Impedance
Active
High Impedance
______________________________________________________________________________________
Drivers/Receivers
The receiver input hysteresis is typically 0.5V with a
guaranteed minimum of 0.2V. This produces clear output transitions with slow-moving input signals, even
with moderate amounts of noise and ringing. The
receiver propagation delay is typically 600ns and is
independent of input swing direction.
Low-Power Receive Mode
The low-power receive-mode feature of the MAX223,
MAX242, and MAX245–MAX249 puts the IC into shutdown mode but still allows it to receive information. This
is important for applications where systems are periodically awakened to look for activity. Using low-power
receive mode, the system can still receive a signal that
will activate it on command and prepare it for communication at faster data rates. This operation conserves
system power.
Negative Threshold—MAX243
The MAX243 is pin compatible with the MAX232A, differing only in that RS-232 cable fault protection is removed
on one of the two receiver inputs. This means that control
lines such as CTS and RTS can either be driven or left
floating without interrupting communication. Different
cables are not needed to interface with different pieces of
equipment.
The input threshold of the receiver without cable fault
protection is -0.8V rather than +1.4V. Its output goes
positive only if the input is connected to a control line
that is actively driven negative. If not driven, it defaults
to the 0 or “OK to send” state. Normally‚ the MAX243’s
other receiver (+1.4V threshold) is used for the data line
(TD or RD)‚ while the negative threshold receiver is connected to the control line (DTR‚ DTS‚ CTS‚ RTS, etc.).
Other members of the RS-232 family implement the
optional cable fault protection as specified by EIA/TIA232E specifications. This means a receiver output goes
high whenever its input is driven negative‚ left floating‚
or shorted to ground. The high output tells the serial
communications IC to stop sending data. To avoid this‚
the control lines must either be driven or connected
with jumpers to an appropriate positive voltage level.
Shutdown—MAX222–MAX242
On the MAX222‚ MAX235‚ MAX236‚ MAX240‚ and
MAX241‚ all receivers are disabled during shutdown.
On the MAX223 and MAX242‚ two receivers continue to
operate in a reduced power mode when the chip is in
shutdown. Under these conditions‚ the propagation
delay increases to about 2.5µs for a high-to-low input
transition. When in shutdown, the receiver acts as a
CMOS inverter with no hysteresis. The MAX223 and
MAX242 also have a receiver output enable input (EN
for the MAX242 and EN for the MAX223) that allows
receiver output control independent of SHDN (SHDN
for MAX241). With all other devices‚ SHDN (SHDN for
MAX241) also disables the receiver outputs.
The MAX225 provides five transmitters and five
receivers‚ while the MAX245 provides ten receivers and
eight transmitters. Both devices have separate receiver
and transmitter-enable controls. The charge pumps
turn off and the devices shut down when a logic high is
applied to the ENT input. In this state, the supply current drops to less than 25µA and the receivers continue
to operate in a low-power receive mode. Driver outputs
enter a high-impedance state (three-state mode). On
the MAX225‚ all five receivers are controlled by the
ENR input. On the MAX245‚ eight of the receiver outputs are controlled by the ENR input‚ while the remaining two receivers (RA5 and RB5) are always active.
RA1–RA4 and RB1–RB4 are put in a three-state mode
when ENR is a logic high.
Receiver and Transmitter Enable
Control Inputs
The MAX225 and MAX245–MAX249 feature transmitter
and receiver enable controls.
The receivers have three modes of operation: full-speed
receive (normal active)‚ three-state (disabled)‚ and lowpower receive (enabled receivers continue to function
at lower data rates). The receiver enable inputs control
the full-speed receive and three-state modes. The
transmitters have two modes of operation: full-speed
transmit (normal active) and three-state (disabled). The
transmitter enable inputs also control the shutdown
mode. The device enters shutdown mode when all
transmitters are disabled. Enabled receivers function in
the low-power receive mode when in shutdown.
______________________________________________________________________________________
15
MAX220–MAX249
nominal 5kΩ values. The receivers implement Type 1
interpretation of the fault conditions of V.28 and
EIA/TIA-232E.
MAX220–MAX249
Drivers/Receivers
Tables 1a–1d define the control states. The MAX244
has no control pins and is not included in these tables.
The MAX246 has ten receivers and eight drivers with
two control pins, each controlling one side of the
device. A logic high at the A-side control input (ENA)
causes the four A-side receivers and drivers to go into
a three-state mode. Similarly, the B-side control input
(ENB) causes the four B-side drivers and receivers to
go into a three-state mode. As in the MAX245, one Aside and one B-side receiver (RA5 and RB5) remain
active at all times. The entire device is put into shutdown mode when both the A and B sides are disabled
(ENA = ENB = +5V).
The MAX247 provides nine receivers and eight drivers
with four control pins. The ENRA and ENRB receiver
enable inputs each control four receiver outputs. The
ENTA and ENTB transmitter enable inputs each control
four drivers. The ninth receiver (RB5) is always active.
The device enters shutdown mode with a logic high on
both ENTA and ENTB.
The MAX248 provides eight receivers and eight drivers
with four control pins. The ENRA and ENRB receiver
enable inputs each control four receiver outputs. The
ENTA and ENTB transmitter enable inputs control four
drivers each. This part does not have an always-active
receiver. The device enters shutdown mode and transmitters go into a three-state mode with a logic high on
both ENTA and ENTB.
16
The MAX249 provides ten receivers and six drivers with
four control pins. The ENRA and ENRB receiver enable
inputs each control five receiver outputs. The ENTA
and ENTB transmitter enable inputs control three drivers each. There is no always-active receiver. The
device enters shutdown mode and transmitters go into
a three-state mode with a logic high on both ENTA and
ENTB. In shutdown mode, active receivers operate in a
low-power receive mode at data rates up to
20kbits/sec.
__________Applications Information
Figures 5 through 25 show pin configurations and typical operating circuits. In applications that are sensitive
to power-supply noise, VCC should be decoupled to
ground with a capacitor of the same value as C1 and
C2 connected as close as possible to the device.
______________________________________________________________________________________
Drivers/Receivers
MAX220–MAX249
+5V INPUT
C3
TOP VIEW
C5
C1+ 1
16 VCC
V+ 2
15 GND
C1- 3
14 T1OUT
MAX220
MAX232
MAX232A
C2+ 4
C2- 5
1
C1
C2
13 R1IN
11 T1IN
T2OUT 7
TTL/CMOS
INPUTS
10 T2IN
9
R2IN 8
R2OUT
DIP/SO
DEVICE
MAX220
MAX232
MAX232A
-10V
C4
T1OUT 14
RS-232
OUTPUTS
400kΩ
10 T2IN
T2OUT 7
R1IN 13
TTL/CMOS
OUTPUTS
C5
4.7
1.0
0.1
6
V-
+5V
12 R1OUT
CAPACITANCE (µF)
C1 C2 C3 C4
4.7 4.7 10 10
1.0 1.0 1.0 1.0
0.1 0.1 0.1 0.1
V+ 2 +10V
3 C14
C2+
+10V TO -10V
5 C2- VOLTAGE INVERTER
+5V
400kΩ
11 T1IN
12 R1OUT
V- 6
16
VCC
+5V TO +10V
VOLTAGE DOUBLER
C1+
RS-232
INPUTS
5kΩ
R2IN 8
9 R2OUT
5kΩ
GND
15
Figure 5. MAX220/MAX232/MAX232A Pin Configuration and Typical Operating Circuit
+5V INPUT C3
ALL CAPACITORS = 0.1µF
TOP VIEW
C5
17
VCC
3 +10V
C1+
+5V TO +10V
V+
4 C1- VOLTAGE DOUBLER
5
C2+
7 -10V
+10V TO -10V
V6 C2C4
VOLTAGE INVERTER
2
(N.C.) EN 1
(N.C.) EN 1
C1+ 2
19 VCC
C1+ 2
17 VCC
V+ 3
18 GND
V+ 3
16 GND
C1- 4
17 T1OUT
C1- 4
15 T1OUT
C2+ 5
14 R1IN
C2- 6
C2+ 5
C2- 6
18 SHDN
MAX222
MAX242
13 R1OUT
V- 7
12 T1IN
T2OUT 8
11 T2IN
R2IN 9
10 R2OUT
DIP/SO
MAX222
MAX242
C2
+5V
400kΩ
12 T1IN
16 N.C.
15 R1IN
V- 7
T2OUT
C1
20 SHDN
14 R1OUT
8
13 N.C.
R2IN 9
12 T1IN
R2OUT 10
11 T2IN
TTL/CMOS
INPUTS
(EXCEPT MAX220)
T1OUT 15
+5V
400kΩ
11 T2IN
T2OUT 8
13 R1OUT
R1IN 14
TTL/CMOS
OUTPUTS
SSOP
RS-232
INPUTS
5kΩ
R2IN 9
10 R2OUT
1 (N.C.) EN
( ) ARE FOR MAX222 ONLY.
PIN NUMBERS IN TYPICAL OPERATING CIRCUIT ARE FOR DIP/SO PACKAGES ONLY.
RS-232
OUTPUTS
(EXCEPT MAX220)
5kΩ
SHDN
GND
18
16
Figure 6. MAX222/MAX242 Pin Configurations and Typical Operating Circuit
______________________________________________________________________________________
17
MAX220–MAX249
Drivers/Receivers
+5V
TOP VIEW
0.1
+5V
28
VCC
27
VCC
400kΩ
T1IN
3
ENR 1
28 VCC
ENR 2
27 VCC
T1IN 3
26 ENT
T2IN 4
25 T3IN
R1OUT 5
MAX225
24 T4IN
R2OUT 6
23 T5IN
R3OUT 7
22 R4OUT
R3IN 8
21 R5OUT
R2IN 9
20 R5IN
R1IN 10
19 R4IN
T1OUT 11
18 T3OUT
T2OUT 12
17 T4OUT
GND 13
16 T5OUT
GND 14
15 T5OUT
SO
T1OUT
+5V
11
400kΩ
T2IN
4
T2OUT
+5V
12
400kΩ
T3IN
25
T3OUT
+5V
18
400kΩ
T4IN
24
T4OUT
+5V
17
400kΩ
T5OUT
T5IN
23
ENT
26
T5OUT
R1OUT
5
R1IN
16
15
10
5kΩ
R2OUT
6
R2IN
9
5kΩ
R3OUT
7
MAX225 FUNCTIONAL DESCRIPTION
5 RECEIVERS
5 TRANSMITTERS
2 CONTROL PINS
1 RECEIVER ENABLE (ENR)
1 TRANSMITTER ENABLE (ENT)
R3IN
5kΩ
R4OUT
22
R4IN
R5OUT
R5IN
5kΩ
1
2
ENR
ENR
GND
13
GND
14
Figure 7. MAX225 Pin Configuration and Typical Operating Circuit
18
19
5kΩ
21
PINS (ENR, GND, VCC, T5OUT) ARE INTERNALLY CONNECTED.
CONNECT EITHER OR BOTH EXTERNALLY. T5OUT IS A SINGLE DRIVER.
8
______________________________________________________________________________________
20
Drivers/Receivers
MAX220–MAX249
+5V INPUT
TOP VIEW
1.0µF
12
11
VCC
+5V TO +10V
VOLTAGE DOUBLER
C1+
1.0µF
14
C115
C2+
1.0µF
16 C2-
1.0µF
V+
+10V TO -10V
VOLTAGE INVERTER
V-
13
17
1.0µF
+5V
400kΩ
7 T1IN
T3OUT 1
28 T4OUT
T1OUT 2
27 R3IN
T2OUT 3
25 SHDN (SHDN)
R2OUT 5
T2IN 6
24 EN (EN)
MAX223
MAX241
T1IN 7
400kΩ
6 T2IN
GND 10
19 R5OUT*
VCC 11
18 R5IN*
C1+ 12
17 V-
V+ 13
16 C2-
C1- 14
15 C2+
Wide SO/
SSOP
RS-232
OUTPUTS
T3
T3OUT 1
+5V
400kΩ
21 T4IN
20 T3IN
T2OUT 3
400kΩ
20 T3IN
23 R4IN*
R1IN 9
T2
+5V
TTL/CMOS
INPUTS
22 R4OUT*
R1OUT 8
T1OUT 2
+5V
26 R3OUT
R2IN 4
T1
21 T4IN
8 R1OUT
T4
T4OUT 28
R1
R1IN 9
5kΩ
5 R2OUT
R2
R2IN 4
5kΩ
LOGIC
OUTPUTS
26 R3OUT
R3
R3IN
27
5kΩ
22 R4OUT
R4
R4IN
RS-232
INPUTS
23
5kΩ
19 R5OUT
R5
*R4 AND R5 IN MAX223 REMAIN ACTIVE IN SHUTDOWN
NOTE: PIN LABELS IN ( ) ARE FOR MAX241
24 EN (EN)
GND
R5IN
18
5kΩ
SHDN 25
(SHDN)
10
Figure 8. MAX223/MAX241 Pin Configuration and Typical Operating Circuit
______________________________________________________________________________________
19
MAX220–MAX249
Drivers/Receivers
+5V INPUT
1.0µF
TOP VIEW
1.0µF
T3OUT
20 T4OUT
1
T1OUT 2
19 T5IN
T2OUT 3
18 N.C.
T2IN 4
1.0µF
MAX230
11
+10V TO -10V
C2+
12
C2- VOLTAGE INVERTER
15 T4IN
VCC 7
14 T3IN
C1+
13 V-
8
V+ 9
12 C2-
C1- 10
11 C2+
13
1.0µF
400kΩ
5 T1IN
T1OUT 2
T1
+5V
16 T5OUT
GND 6
V-
1.0µF
+5V
17 SHDN
T1IN 5
7
VCC
V+ 9
+5V TO +10V
VOLTAGE DOUBLER
8 C1+
10 C1-
400kΩ
4 T2IN
T2OUT 3
T2
+5V
400kΩ
TTL/CMOS
INPUTS
14 T3IN
T3OUT 1
T3
RS-232
OUTPUTS
+5V
400kΩ
15 T4IN
T4OUT 20
T4
+5V
400kΩ
DIP/SO
19 T5IN
T5OUT 16
T5
N.C. x 18
17
GND
SHDN
6
+5V INPUT
TOP VIEW
+7.5V TO +12V
1.0µF
13 (15)
1
2
1.0µF
C+ 1
CV-
2
3
T2OUT 4
14 V+
C+ 1
16 V+
13 VCC
C- 2
15 VCC
V- 3
12 GND
MAX231
R2IN 5
11 T1OUT
T2OUT 4
9
R1OUT
T2IN 7
8
T1IN
R2OUT 6
8
10 T1IN
N.C. 8
9
N.C.
DIP
SO
V-
T1IN
T1OUT 11
T1
C2
1.0µF
(13)
RS-232
OUTPUTS
(11)
7
T2IN
9
R1OUT
T2OUT 4
T2
R1IN 10
R1
TTL/CMOS
OUTPUTS
5kΩ
6 R2OUT
R2IN 5
R2
(12)
RS-232
INPUTS
GND
12 (14)
Figure 10. MAX231 Pin Configurations and Typical Operating Circuit
20
(16)
400kΩ
5kΩ
PIN NUMBERS IN ( ) ARE FOR SO PACKAGE
14
3
+5V
TTL/CMOS
INPUTS
11 R1OUT
T2IN 7
V+
400kΩ
(10)
12 R1IN
R2IN 5
10 R1IN
R2OUT 6
13 T1OUT
C1-
VCC
+12V TO -12V
VOLTAGE CONVERTER
+5V
14 GND
MAX231
C1+
______________________________________________________________________________________
Drivers/Receivers
MAX220–MAX249
+5V INPUT
1.0µF
TOP VIEW
7
VCC
+5V
400kΩ
T2IN
1
T1IN 2
19 R2IN
R1OUT 3
GND 6
17 V-
MAX233
MAX233A
(V+) C1+
14 V+ (C1-)
GND 9
12 V- (C2+)
(V-) CS- 10
RS-232
OUTPUTS
400kΩ
1
T2IN
3
R1OUT
T2OUT
18
R1IN 4
11 C2+ (C2-)
DIP/SO
5kΩ
TTL/CMOS
OUTPUTS
20 R2OUT
13 C1- (C1+)
8
+5V
16 C215 C2+
VCC 7
T1OUT 5
T1IN
TTL/CMOS
INPUTS
18 T2OUT
R1IN 4
T1OUT 5
2
20 R2OUT
8 (13)
DO NOT MAKE
CONNECTIONS TO 13 (14)
THESE PINS
12 (10)
INTERNAL -10
17
POWER SUPPLY
INTERNAL +10V
POWER SUPPLY
RS-232
OUTPUTS
R2IN 19
5kΩ C2+ 11 (12)
C1+
C1-
C2+
V-
C2-
V14 (8) V+
C2GND
15
16
10 (11)
GND
6
9
( ) ARE FOR SO PACKAGE ONLY.
Figure 11. MAX233/MAX233A Pin Configuration and Typical Operating Circuit
+5V INPUT
1.0µF
TOP VIEW
7
1.0µF
9
10
1.0µF
T1OUT 1
16 T3OUT
T2OUT 2
C1C2+
11 C2-
12 V-
VCC 6
11 C2-
C1+ 7
10 C2+
9
V+ 8
4 T1IN
13 T3IN
GND 5
C1-
+10V TO -10V
VOLTAGE INVERTER
1.0µF
8
V+
V-
12
1.0µF
400kΩ
14 T4IN
MAX234
6
VCC
+5V TO +10V
VOLTAGE DOUBLER
+5V
15 T4OUT
T2IN 3
T1IN 4
C1+
T1
T1OUT 1
+5V
400kΩ
3 T2IN
T2
T2OUT 3
+5V
TTL/CMOS
INPUTS
RS-232
OUTPUTS
400kΩ
13 T3IN
T3
T3OUT 16
+5V
DIP/SO
400kΩ
14 T4IN
T4
T4OUT 15
GND
5
______________________________________________________________________________________
21
MAX220–MAX249
Drivers/Receivers
+5V INPUT
TOP VIEW
1.0µF
12
+5V
VCC
400kΩ
8 T1IN
T1
T1OUT 3
T2
T2OUT 4
+5V
400kΩ
7 T2IN
+5V
400kΩ
TTL/CMOS
INPUTS
T4OUT 1
24 R3IN
T3OUT 2
23 R3OUT
T1OUT 3
22 T5IN
T2OUT 4
21 SHDN
R2IN 5
MAX235
R2OUT 6
15 T3IN
T3OUT 2
T3
+5V
400kΩ
16 T4IN
22 T5IN
T4OUT 1
T4
+5V
20 EN
400kΩ
T5OUT 19
T5
19 T5OUT
T2IN 7
18 R4IN
T1IN 8
17 R4OUT
R1OUT 9
16 T4IN
R1IN 10
15 T3IN
GND 11
14 R5OUT
VCC 12
13 R5IN
DIP
9 R1OUT
R1IN 10
T1
5kΩ
6 R2OUT
R2IN 5
R2
5kΩ
TTL/CMOS
OUTPUTS
23 R3OUT
R3IN 24
R3
5kΩ
17 R4OUT
R4IN 18
R4
5kΩ
14 R5OUT
R5IN 13
R5
5kΩ
20 EN
SHDN
21
GND
11
22
RS-232
OUTPUTS
______________________________________________________________________________________
RS-232
INPUTS
Drivers/Receivers
MAX220–MAX249
TOP VIEW
+5V INPUT
1.0µF
9
10
1.0µF
12
13
1.0µF
1.0µF
VCC
+5V TO +10V
VOLTAGE DOUBLER
C1+
C1-
V+
C2+
V-
+10V TO -10V
VOLTAGE INVERTER
14 C2-
11
15
1.0µF
+5V
400kΩ
7 T1IN
T3OUT 1
24 T4OUT
T1OUT 2
23 R2IN
T2OUT 3
22 R2OUT
R1IN 4
21 SHDN
R1OUT 5
MAX236
+5V
400kΩ
6 T2IN
TTL/CMOS
INPUTS
19 T4IN
T1IN 7
18 T3IN
GND 8
17 R3OUT
VCC 9
16 R3IN
C1+ 10
15 V-
V+ 11
14 C2-
C1- 12
13 C2+
T2OUT
T2
3
RS-232
OUTPUTS
+5V
400kΩ
20 EN
T2IN 6
T1OUT 2
T1
18 T3IN
T3OUT 1
T3
+5V
400kΩ
19 T4IN
5 R1OUT
T4OUT 24
T4
R1IN 4
R1
5kΩ
DIP/SO
TTL/CMOS
OUTPUTS
22 R2OUT
R2IN
R2
23
RS-232
INPUTS
5kΩ
17 R3OUT
R3IN
R3
16
5kΩ
20 EN
SHDN
21
GND
8
______________________________________________________________________________________
23
MAX220–MAX249
Drivers/Receivers
TOP VIEW
+5V INPUT
1.0µF
10
1.0µF
12
13
1.0µF
14
1.0µF
9
VCC
+5V TO +10V
VOLTAGE DOUBLER
C1+
C1C2+
V+
V-
+10V TO -10V
VOLTAGE INVERTER
C2-
11
15
1.0µF
+5V
400kΩ
T3OUT 1
24 T4OUT
T1OUT 2
23 R2IN
T2OUT 3
22 R2OUT
R1IN 4
R1OUT 5
7 T1IN
400kΩ
6 T2IN
21 T5IN
MAX237
T2IN 6
+5V
20 T5OUT
19 T4IN
T1IN 7
18 T3IN
GND 8
17 R3OUT
VCC 9
16 R3IN
C1+ 10
15 V-
V+ 11
14 C2-
C1- 12
13 C2+
T1OUT 2
T1
+5V
T2OUT
T2
3
400kΩ
TTL/CMOS
INPUTS
18 T3IN
+5V
T3OUT 1
T3
RS-232
OUTPUTS
400kΩ
19 T4IN
+5V
T4OUT 24
T4
400kΩ
21 T5IN
DIP/SO
5 R1OUT
T5OUT 20
T5
R1
R1IN 4
5kΩ
TTL/CMOS
OUTPUTS
22 R2OUT
R2
R2IN
23
5kΩ
17 R3OUT
R3
R3IN
5kΩ
GND
8
24
______________________________________________________________________________________
16
RS-232
INPUTS
Drivers/Receivers
MAX220–MAX249
TOP VIEW
+5V INPUT
1.0µF
1.0µF
9
10
1.0µF
12
13
1.0µF
14
VCC
+5V TO +10V
VOLTAGE DOUBLER
C1+
C1-
V+
C2+
V-
+10V TO -10V
VOLTAGE INVERTER
C2-
11
15
1.0µF
+5V
400kΩ
T2OUT 1
24 T3OUT
T1OUT 2
23 R3IN
R2IN 3
T1OUT 2
T1
+5V
400kΩ
22 R3OUT
R2OUT 4
T1IN 5
5 T1IN
18 T2IN
21 T4IN
MAX238
20 T4OUT
R1OUT 6
19 T3IN
R1IN 7
18 T2IN
GND 8
17 R4OUT
VCC 9
16 R4IN
C1+ 10
15 V-
V+ 11
14 C2-
C1- 12
13 C2+
T2OUT
T2
1
+5V
TTL/CMOS
INPUTS
RS-232
OUTPUTS
400kΩ
19 T3IN
T3OUT 24
T3
+5V
400kΩ
21 T4IN
6 R1OUT
T4OUT 20
T4
R1
R1IN 7
5kΩ
DIP/SO
4 R2OUT
R2
TTL/CMOS
OUTPUTS
R2IN
3
RS-232
INPUTS
5kΩ
22 R3OUT
R3
R3IN
23
5kΩ
17 R4OUT
R4
R4IN
16
5kΩ
GND
8
______________________________________________________________________________________
25
MAX220–MAX249
Drivers/Receivers
TOP VIEW
7.5V TO 13.2V
INPUT
+5V INPUT
1.0µF
4
6
1.0µF
7
5
VCC
C1+
V+
V-
+10V TO -10V
VOLTAGE INVERTER
C1-
8
1.0µF
+5V
400kΩ
24 T1IN
R1OUT 1
24 T1IN
R1IN 2
23 T2IN
GND 3
22 R2OUT
T1OUT 19
T1
+5V
400kΩ
VCC 4
V+ 5
TTL/CMOS
INPUTS
23 T2IN
19 T1OUT
C- 7
18 R3IN
V- 8
17 R3OUT
R5IN 9
16 T3IN
R5OUT 10
15 N.C.
R4OUT 11
14 EN
RS-232
OUTPUTS
400kΩ
20 T2OUT
C+ 6
20
+5V
21 R2IN
MAX239
T2OUT
T2
16 T3IN
1 R1OUT
T3OUT 13
T3
R1
R1IN 2
5kΩ
22 R2OUT
R2
13 T3OUT
R4IN 12
R2IN 21
5kΩ
DIP/SO
TTL/CMOS
OUTPUTS
17 R3OUT
R3
R3IN
18
5kΩ
11 R4OUT
R4
R4IN
12
5kΩ
10 R5OUT
R5
R5IN
5kΩ
14 EN
N.C.
GND
3
26
______________________________________________________________________________________
9
15
RS-232
INPUTS
Drivers/Receivers
MAX220–MAX249
+5V INPUT
1.0µF
TOP VIEW
25
19
VCC
+5V TO +10V
VOLTAGE DOUBLER
C1+
1.0µF
27
C128
C2+
1.0µF
29 C2-
1.0µF
V+
+5V TO -10V
VOLTAGE INVERTER
V-
26
30
1.0µF
+5V
400kΩ
15 T1IN
T1
+5V
400kΩ
N.C.
R2IN
N.C.
T2OUT
T1OUT
T3OUT
T4OUT
R3IN
R3OUT
T5IN
N.C.
14 T2IN
T2
+5V
11
10
9
8
7
6
5
4
3
2
1
TTL/CMOS
INPUTS
T3
12
13
14
15
16
17
18
19
20
21
22
MAX240
44
43
42
41
40
39
38
37
36
35
34
N.C.
SHDN
EN
T5OUT
R4IN
R4OUT
T4IN
T3IN
R5OUT
R5IN
N.C.
+5V
2 T5IN
16 R1OUT
N.C.
N.C.
C1+
V+
C1C2+
C2
VN.C.
N.C.
N.C.
8
T3OUT 6
RS-232
OUTPUTS
400kΩ
38 T4IN
T4
T4OUT 5
400kΩ
T5
R1
T5OUT
41
R1IN 17
5kΩ
13 R2OUT
R2
23
24
25
26
27
28
29
30
31
32
33
N.C.
R2OUT
T2IN
T1IN
R1OUT
R1IN
GND
VCC
N.C.
N.C.
N.C.
T2OUT
400kΩ
37 T3IN
+5V
T1OUT 7
R2IN 10
5kΩ
TTL/CMOS
OUTPUTS
3 R3OUT
R3
R3IN
4
5kΩ
RS-232
INPUTS
Plastic FP
39 R4OUT
R4
R4IN
40
5kΩ
36 R5OUT
R5
R5IN
35
5kΩ
42 EN
GND
SHDN
43
18
______________________________________________________________________________________
27
MAX220–MAX249
Drivers/Receivers
+5V INPUT
TOP VIEW
0.1µF
1
C1+ 1
16 VCC
V+ 2
15 GND
C1- 3
14 T1OUT
C2+ 4
MAX243
0.1µF
3 C14
C2+
0.1µF
5 C2-
11 T1IN
T2OUT 7
10 T2IN
9
V+
+10V TO -10V
VOLTAGE INVERTER
V-
2
+10V
6
-10V
0.1µF
400kΩ
13 R1IN
V- 6
R2IN 8
16
VCC
+5V TO +10V
VOLTAGE DOUBLER
+5V
T1OUT 14
11 T1IN
12 R1OUT
C2- 5
C1+
ALL CAPACITORS = 0.1µF
0.1µF
+5V
TTL/CMOS
INPUTS
RS-232
OUTPUTS
400kΩ
T2OUT 7
10 T2IN
R2OUT
DIP/SO
12 R1OUT
R1IN 13
TTL/CMOS
OUTPUTS
9 R2OUT
RECEIVER INPUT
≤ -3 V
OPEN
≥ +3V
R1 OUTPUT
HIGH
HIGH
LOW
R2 OUTPUT
HIGH
LOW
LOW
R2IN 8
5kΩ
GND
15
28
RS-232
INPUTS
5kΩ
______________________________________________________________________________________
Drivers/Receivers
MAX220–MAX249
+5V
TOP VIEW
1µF
1µF
20
VCC
+5V TO +10V VOLTAGE DOUBLER
1µF
RB5IN
TB4OUT
TB3OUT
TB2OUT
TB1OUT
TA1OUT
TA2OUT
TA4OUT
TA3OUT
RA4IN
RA5IN
21
1µF
6
5
4
3
2
1
44 43 42 41 40
C1+
23 C124
C2+
25 C2-
22
V+
26
V- 1µF
+10V TO -10V VOLTAGE INVERTER
2 TA1OUT
+5V
+5V
TB1OUT 44
400kΩ
RA3IN
7
39 RB4IN
RA2IN
8
38 RB3IN
RA1IN
9
37 RB2IN
RA1OUT
10
36 RB1IN
RA2OUT
11
35 RB1OUT
RA3OUT
12
RA4OUT
13
33 RB3OUT
RA5OUT
14
32 RB4OUT
MAX244
34 RB2OUT
31 RB5OUT
16
30 TB1IN
TA3IN
17
29 TB2IN
TB3IN
TB4IN
V-
C2-
C2+
V+
C1-
VCC
19 20 21 22 23 24 25 26 27 28
C1+
18
GND
15
TA4IN
TA1IN
TA2IN
PLCC
15 TA1IN
2 TA2OUT
TB1IN 30
+5V
+5V
16 TA2IN
TB2IN 29
3 TA3OUT
+5V
+5V
TB3OUT 42
400kΩ
17 TA3IN
TB3IN 28
4 TA4OUT
+5V
+5V
TB4OUT 41
400kΩ
18 TA4IN
TB4IN 27
9 RA1IN
RB1IN 36
5kΩ
5kΩ
10 RA1OUT
RB1OUT 35
8 RA2IN
10 RECEIVERS
5 A-SIDE RECEIVER
5 B-SIDE RECEIVER
8 TRANSMITTERS
4 A-SIDE TRANSMITTERS
4 B-SIDE TRANSMITTERS
NO CONTROL PINS
TB2OUT 43
400kΩ
RB2IN 37
5kΩ
5kΩ
11 RA2OUT
RB2OUT 34
7 RA3IN
RB3IN 38
5kΩ
5kΩ
12 RA3OUT
RB3OUT 33
6 RA4IN
RB4IN 39
5kΩ
5kΩ
13 RA4OUT
RB4OUT 32
5 RA5IN
RB5IN 40
5kΩ
5kΩ
14 RA5OUT
GND
19
RB5OUT 31
______________________________________________________________________________________
29
MAX220–MAX249
Drivers/Receivers
+5V
TOP VIEW
1µF
40
VCC
ENR
40
1
VCC
TA1IN
2
39
ENT
TA2IN
3
38
TB1IN
TA3IN
4
37
TB2IN
TA4IN
5
36
TB3IN
RA5OUT
6
35
TB4IN
RA4OUT
7
34
RB5OUT
MAX245
RA3OUT
8
33
RB4OUT
RA2OUT
9
32
RB3OUT
RA1OUT
10
31
RB2OUT
RA1IN
11
30
RB1OUT
RA2IN
12
29
RB1IN
RA3IN
13
28
RB2IN
RA4IN
14
27
RB3IN
RA5IN
15
26
RB4IN
TA1OUT
16
25
RB5IN
TA2OUT
17
24
TB1OUT
TA3OUT
18
23
TB2OUT
TA4OUT
GND
19
22
TB3OUT
20
21
TB4OUT
16 TA1OUT
+5V
+5V
2 TA1IN
TB1IN 38
17 TA2OUT
+5V
+5V
3 TA2IN
TB2IN 37
18 TA3OUT
+5V
+5V
TB3OUT 22
400kΩ
4 TA3IN
TB3IN 36
19 TA4OUT
+5V
+5V
TB4OUT 21
400kΩ
5 TA4IN
TB4IN 35
1 ENR
ENT 39
11 RA1IN
RB1IN 29
5kΩ
5kΩ
10 RA1OUT
RB1OUT 30
12 RA2IN
RB2IN 28
5kΩ
5kΩ
RB2OUT 31
13 RA3IN
RB3IN 27
5kΩ
10 RECEIVERS
5 A-SIDE RECEIVERS (RA5 ALWAYS ACTIVE)
5 B-SIDE RECEIVERS (RB5 ALWAYS ACTIVE)
8 TRANSMITTTERS
2 CONTROL PINS
1 RECEIVER ENABLE (ENR)
1 TRANSMITTER ENABLE (ENT)
TB2OUT 23
400kΩ
9 RA2OUT
DIP
TB1OUT 24
400kΩ
5kΩ
8 RA3OUT
RB3OUT 32
14 RA4IN
RB4IN 26
5kΩ
5kΩ
7 RA4OUT
RB4OUT 33
15 RA5IN
RB5IN 25
5kΩ
5kΩ
6 RA5OUT
RB5OUT 34
GND
20
30
______________________________________________________________________________________
Drivers/Receivers
MAX220–MAX249
+5V
TOP VIEW
1µF
ENA
1
40
VCC
TA1IN
2
39
ENB
TA2IN
3
38
TB1IN
TA3IN
4
37
TB2IN
TA4IN
5
36
TB3IN
RA5OUT
6
35
TB4IN
RA4OUT
7
34
RB5OUT
RA3OUT
8
33
RB4OUT
MAX246
RA2OUT
9
32
RB3OUT
RA1OUT
10
31
RB2OUT
RA1IN
11
30
RB1OUT
RA2IN
12
29
RB1IN
RA3IN
13
28
RB2IN
RA4IN
14
27
RB3IN
RA5IN
15
26
RB4IN
TA1OUT
16
25
RB5IN
TA2OUT
17
24
TB1OUT
TA3OUT
18
23
TB2OUT
TA4OUT
19
22
TB3OUT
GND
20
21
TB4OUT
DIP
40
VCC
+5V
+5V
16 TA1OUT
TB1OUT 24
400kΩ
2 TA1IN
TB1IN 38
+5V
+5V
17 TA2OUT
TB2OUT 23
400kΩ
3 TA2IN
TB2IN 37
+5V
+5V
18 TA3OUT
TB3OUT 22
400kΩ
4 TA3IN
TB3IN 36
+5V
+5V
TB4OUT 21
19 TA4OUT
400kΩ
5 TA4IN
TB4IN 35
1 ENA
ENB 39
RB1IN 29
11 RA1IN
5kΩ
5kΩ
10 RA1OUT
RB1OUT 30
12 RA2IN
RB2IN 28
5kΩ
5kΩ
9 RA2OUT
RB2OUT 31
13 RA3IN
10 RECEIVERS
5 A-SIDE RECEIVERS (RA5 ALWAYS ACTIVE)
8 TRANSMITTERS
2 CONTROL PINS
ENABLE A-SIDE (ENA)
ENABLE B-SIDE (ENB)
RB3IN 27
5kΩ
5kΩ
8 RA3OUT
RB3OUT 32
14 RA4IN
RB4IN 26
5kΩ
5kΩ
7 RA4OUT
RB4OUT 33
15 RA5IN
RB5IN 25
5kΩ
6 RA5OUT
5kΩ
RB5OUT 34
GND
20
______________________________________________________________________________________
31
MAX220–MAX249
Drivers/Receivers
+5V
TOP VIEW
1µF
40
VCC
+5V
+5V
1 ENTA
ENTA
1
40
VCC
TA1IN
2
39
ENTB
TA2IN
3
38
TB1IN
TA3IN
4
37
TB2IN
TA4IN
5
36
TB3IN
RB5OUT
6
35
TB4IN
RA4OUT
7
34
RB4OUT
RA3OUT
8
33
RB3OUT
MAX247
RA2OUT
9
32
RB2OUT
RA1OUT
10
31
RB1OUT
ENRA
11
30
ENRB
RA1IN
12
29
RB1IN
RA2IN
13
28
RB2IN
RA3IN
14
27
RB3IN
RA4IN
15
26
RB4IN
TA1OUT
16
25
RB5IN
TA2OUT
17
24
TB1OUT
TA3OUT
18
23
TB2OUT
TA4OUT
19
22
TB3OUT
GND
20
21
TB4OUT
ENTB 39
TB1OUT 24
16 TA1OUT
400kΩ
2 TA1IN
TB1IN 38
+5V
+5V
17 TA2OUT
TB2OUT 23
400kΩ
3 TA2IN
TB2IN 37
+5V
+5V
18 TA3OUT
TB3OUT 22
400kΩ
4 TA3IN
TB3IN 36
+5V
+5V
TB4OUT 21
19 TA4OUT
400kΩ
5 TA4IN
TB4IN 35
6 RB5OUT
RB5IN 25
5kΩ
12 RA1IN
RB1IN 29
5kΩ
5kΩ
10 RA1OUT
RB1OUT 31
13 RA2IN
RB2IN 28
DIP
5kΩ
9 RECEIVERS
4 A-SIDE RECEIVERS
8 TRANSMITTERS
4 CONTROL PINS
ENABLE RECEIVER A-SIDE (ENRA)
ENABLE RECEIVER B-SIDE (ENRB)
ENABLE RECEIVER A-SIDE (ENTA)
ENABLE RECEIVERr B-SIDE (ENTB)
5kΩ
9 RA2OUT
RB2OUT 32
14 RA3IN
RB3IN 27
5kΩ
5kΩ
8 RA3OUT
RB3OUT 33
15 RA4IN
RB4IN 26
5kΩ
5kΩ
7 RA4OUT
RB4OUT 34
11 ENRA
ENRB 30
GND
20
32
______________________________________________________________________________________
Drivers/Receivers
MAX220–MAX249
TOP VIEW
+5V
1µF
1µF
20
4
3
2
1
44 43 42 41 40
1µF
RB4IN
TA4OUT
TB1OUT
TB3OUT
TA1OUT
TB2OUT
TA2OUT
5
TA4OUT
6
TA3OUT
RA3IN
RA4IN
21
1µF
C1+
23 C124
C2+
25 C2-
VCC
V+
V-
+5V
1 TA1OUT
39 RB3IN
RA1IN
8
38 RB2IN
ENRA
9
37 RB1IN
RA1OUT
10
36 ENRB
RA2OUT
11
35 RB1OUT
RA3OUT
12
RA4OUT
13
33 RB3OUT
TA1IN
14
32 RB4OUT
TA2IN
15
31 TB1IN
TA3IN
16
30 TB2IN
34 RB2OUT
29 TB3IN
TB4IN
ENTB
V-
C2-
C2+
V+
C1-
VCC
19 20 21 22 23 24 25 26 27 28
C1+
18
GND
17
ENTA
TA4IN
MAX248
PLCC
TB1OUT 44
400kΩ
14 TA1IN
TB1IN 31
+5V
+5V
2 TA2OUT
TB2OUT 43
400kΩ
15 TA2IN
TB2IN 30
+5V
+5V
3 TA3OUT
TB3OUT 42
400kΩ
16 TA3IN
TB3IN 29
+5V
+5V
TB4OUT 41
4 TA4OUT
400kΩ
17 TA4IN
TB4IN 28
8 RA1IN
RB1IN 37
5kΩ
8 RECEIVERS
4 A-SIDE RECEIVERS
4 B-SIDE RECEIVERS
8 TRANSMITTERS
4 CONTROL PINS
ENABLE RECEIVER B-SIDE (ENTB)
1µF
ENTB 27
+5V
7
26
18 ENTA
RA2IN
22
5kΩ
10 RA1OUT
RB1OUT 35
7 RA2IN
RB2IN 38
5kΩ
5kΩ
11 RA2OUT
RB2OUT 34
6 RA3IN
RB3IN 39
5kΩ
5kΩ
12 RA3OUT
RB3OUT 33
5 RA4IN
RB4IN 40
5kΩ
5kΩ
13 RA4OUT
9 ENRA
RB4OUT 32
ENRB 36
GND
19
______________________________________________________________________________________
33
MAX220–MAX249
Drivers/Receivers
+5V
TOP VIEW
1µF
1µF
20
2
1
44 43 42 41 40
RB5IN
3
1µF
RB4IN
TB3OUT
TB2OUT
TB1OUT
4
TA1OUT
5
TA3OUT
RA5IN
6
TA2OUT
RA3IN
RA4IN
21
1µF
VCC
C1+
23 C124
C2+
25 C2-
V+
V-
+5V
TB1OUT 44
1 TA1OUT
39 RB3IN
RA1IN
8
38 RB2IN
ENRA
9
37 RB1IN
RA1OUT
10
36 ENRB
RA2OUT
11
35 RB1OUT
RA3OUT
12
RA4OUT
13
33 RB3OUT
RA5OUT
14
32 RB4OUT
MAX249
34 RB2OUT
TA1IN
15
31 RB5OUT
TA2IN
16
30 TB1IN
29 TB2IN
TB3IN
ENTB
V-
C2-
C1-
C2+
V+
VCC
19 20 21 22 23 24 25 26 27 28
C1+
18
GND
17
ENTA
TA3IN
PLCC
400kΩ
15 TA1IN
TB1IN 30
+5V
+5V
2 TA2OUT
TB2OUT 43
400kΩ
16 TA2IN
TB2IN 29
+5V
+5V
3 TA3OUT
TB3OUT 42
400kΩ
17 TA3IN
TB3IN 28
8 RA1IN
RB1IN 37
5kΩ
5kΩ
10 RA1OUT
RB1OUT 35
7 RA2IN
RB2IN 38
5kΩ
10 RECEIVERS
5 A-SIDE RECEIVERS
5 B-SIDE RECEIVERS
6 TRANSMITTERS
4 CONTROL PINS
ENABLE RECEIVER B-SIDE (ENTB)
5kΩ
11 RA2OUT
RB2OUT 34
6 RA3IN
RB3IN 39
5kΩ
5kΩ
12 RA3OUT
RB3OUT 33
5 RA4IN
RB4IN 40
5kΩ
5kΩ
13 RA4OUT
RB4OUT 32
4 RA5IN
RB5IN 41
5kΩ
5kΩ
14 RA5OUT
RB5OUT 31
9 ENRA
ENRB 36
GND
19
34
1µF
ENTB 27
+5V
7
26
18 ENTA
RA2IN
22
______________________________________________________________________________________
Drivers/Receivers
MAX222CPN
PART
TEMP RANGE
0°C to +70°C
18 Plastic DIP
PIN-PACKAGE
PART
MAX232AC/D
TEMP RANGE
0°C to +70°C
PIN-PACKAGE
Dice*
MAX222CWN
0°C to +70°C
18 Wide SO
MAX232AEPE
-40°C to +85°C
16 Plastic DIP
MAX222C/D
0°C to +70°C
Dice*
MAX232AESE
-40°C to +85°C
16 Narrow SO
MAX222EPN
-40°C to +85°C
18 Plastic DIP
MAX232AEWE
-40°C to +85°C
16 Wide SO
MAX222EWN
-40°C to +85°C
18 Wide SO
MAX232AEJE
-40°C to +85°C
16 CERDIP
MAX222EJN
-40°C to +85°C
18 CERDIP
MAX232AMJE
-55°C to +125°C
16 CERDIP
MAX222MJN
-55°C to +125°C
18 CERDIP
MAX232AMLP
-55°C to +125°C
20 LCC
MAX223CAI
0°C to +70°C
28 SSOP
MAX233CPP
0°C to +70°C
20 Plastic DIP
MAX223CWI
0°C to +70°C
28 Wide SO
MAX233EPP
-40°C to +85°C
20 Plastic DIP
MAX223C/D
0°C to +70°C
Dice*
MAX233ACPP
0°C to +70°C
20 Plastic DIP
MAX223EAI
-40°C to +85°C
28 SSOP
MAX233ACWP
0°C to +70°C
20 Wide SO
MAX223EWI
-40°C to +85°C
28 Wide SO
MAX233AEPP
-40°C to +85°C
20 Plastic DIP
MAX225CWI
0°C to +70°C
28 Wide SO
MAX233AEWP
-40°C to +85°C
20 Wide SO
MAX225EWI
-40°C to +85°C
28 Wide SO
MAX234CPE
0°C to +70°C
16 Plastic DIP
MAX230CPP
0°C to +70°C
20 Plastic DIP
MAX234CWE
0°C to +70°C
16 Wide SO
MAX230CWP
0°C to +70°C
20 Wide SO
MAX234C/D
0°C to +70°C
Dice*
MAX230C/D
0°C to +70°C
Dice*
MAX234EPE
-40°C to +85°C
16 Plastic DIP
MAX230EPP
-40°C to +85°C
20 Plastic DIP
MAX234EWE
-40°C to +85°C
16 Wide SO
-40°C to +85°C
16 CERDIP
16 CERDIP
MAX230EWP
-40°C to +85°C
20 Wide SO
MAX234EJE
MAX230EJP
-40°C to +85°C
20 CERDIP
MAX234MJE
-55°C to +125°C
MAX230MJP
-55°C to +125°C
20 CERDIP
MAX235CPG
0°C to +70°C
24 Wide Plastic DIP
MAX231CPD
0°C to +70°C
14 Plastic DIP
MAX235EPG
-40°C to +85°C
24 Wide Plastic DIP
MAX231CWE
0°C to +70°C
16 Wide SO
MAX235EDG
-40°C to +85°C
24 Ceramic SB
0°C to +70°C
14 CERDIP
MAX235MDG
-55°C to +125°C
24 Ceramic SB
MAX231C/D
0°C to +70°C
Dice*
MAX236CNG
0°C to +70°C
24 Narrow Plastic DIP
MAX231EPD
-40°C to +85°C
14 Plastic DIP
MAX236CWG
0°C to +70°C
24 Wide SO
MAX231EWE
-40°C to +85°C
16 Wide SO
MAX236C/D
0°C to +70°C
Dice*
MAX231EJD
-40°C to +85°C
14 CERDIP
MAX236ENG
-40°C to +85°C
14 CERDIP
MAX236EWG
-40°C to +85°C
24 Wide SO
MAX231CJD
MAX231MJD
-55°C to +125°C
MAX232CPE
0°C to +70°C
16 Plastic DIP
MAX236ERG
-40°C to +85°C
24 Narrow CERDIP
MAX232CSE
0°C to +70°C
16 Narrow SO
MAX236MRG
-55°C to +125°C
24 Narrow CERDIP
MAX232CWE
0°C to +70°C
16 Wide SO
MAX237CNG
0°C to +70°C
MAX232C/D
0°C to +70°C
Dice*
MAX237CWG
0°C to +70°C
24 Wide SO
MAX232EPE
-40°C to +85°C
16 Plastic DIP
MAX237C/D
0°C to +70°C
Dice*
MAX232ESE
-40°C to +85°C
16 Narrow SO
MAX237ENG
-40°C to +85°C
MAX232EWE
-40°C to +85°C
16 Wide SO
MAX237EWG
-40°C to +85°C
24 Wide SO
MAX232EJE
-40°C to +85°C
16 CERDIP
MAX237ERG
-40°C to +85°C
24 Narrow CERDIP
MAX232MJE
-55°C to +125°C
16 CERDIP
MAX237MRG
-55°C to +125°C
24 Narrow CERDIP
MAX232MLP
-55°C to +125°C
20 LCC
MAX238CNG
0°C to +70°C
MAX232ACPE
0°C to +70°C
16 Plastic DIP
MAX238CWG
0°C to +70°C
24 Wide SO
MAX232ACSE
0°C to +70°C
16 Narrow SO
MAX238C/D
0°C to +70°C
Dice*
MAX232ACWE
0°C to +70°C
16 Wide SO
MAX238ENG
-40°C to +85°C
* Contact factory for dice specifications.
______________________________________________________________________________________
35
MAX220–MAX249
___________________________________________Ordering Information (continued)
MAX220–MAX249
Drivers/Receivers
___________________________________________Ordering Information (continued)
MAX238EWG
PART
-40°C to +85°C
TEMP RANGE
24 Wide SO
PIN-PACKAGE
PART
MAX243CPE
TEMP RANGE
0°C to +70°C
PIN-PACKAGE
16 Plastic DIP
MAX238ERG
-40°C to +85°C
24 Narrow CERDIP
MAX243CSE
0°C to +70°C
16 Narrow SO
MAX238MRG
-55°C to +125°C
24 Narrow CERDIP
MAX243CWE
0°C to +70°C
16 Wide SO
MAX239CNG
0°C to +70°C
MAX243C/D
0°C to +70°C
Dice*
MAX239CWG
0°C to +70°C
24 Wide SO
MAX243EPE
-40°C to +85°C
16 Plastic DIP
MAX239C/D
0°C to +70°C
Dice*
MAX243ESE
-40°C to +85°C
16 Narrow SO
MAX239ENG
-40°C to +85°C
MAX243EWE
-40°C to +85°C
16 Wide SO
MAX239EWG
-40°C to +85°C
24 Wide SO
MAX243EJE
-40°C to +85°C
16 CERDIP
MAX239ERG
-40°C to +85°C
24 Narrow CERDIP
MAX243MJE
-55°C to +125°C
16 CERDIP
MAX239MRG
-55°C to +125°C
24 Narrow CERDIP
MAX244CQH
0°C to +70°C
44 PLCC
MAX240CMH
0°C to +70°C
44 Plastic FP
MAX244C/D
0°C to +70°C
Dice*
MAX240C/D
0°C to +70°C
Dice*
MAX244EQH
-40°C to +85°C
MAX241CAI
0°C to +70°C
28 SSOP
MAX245CPL
0°C to +70°C
40 Plastic DIP
0°C to +70°C
28 Wide SO
MAX245C/D
0°C to +70°C
Dice*
MAX241C/D
0°C to +70°C
Dice*
MAX245EPL
-40°C to +85°C
40 Plastic DIP
MAX241EAI
-40°C to +85°C
28 SSOP
MAX246CPL
0°C to +70°C
40 Plastic DIP
MAX241EWI
-40°C to +85°C
28 Wide SO
MAX246C/D
0°C to +70°C
Dice*
20 SSOP
MAX246EPL
-40°C to +85°C
40 Plastic DIP
0°C to +70°C
40 Plastic DIP
Dice*
MAX241CWI
MAX242CAP
0°C to +70°C
44 PLCC
MAX242CPN
0°C to +70°C
18 Plastic DIP
MAX247CPL
MAX242CWN
0°C to +70°C
18 Wide SO
MAX247C/D
0°C to +70°C
MAX242C/D
0°C to +70°C
Dice*
MAX247EPL
-40°C to +85°C
MAX242EPN
-40°C to +85°C
18 Plastic DIP
MAX248CQH
0°C to +70°C
44 PLCC
MAX242EWN
-40°C to +85°C
18 Wide SO
MAX248C/D
0°C to +70°C
Dice*
40 Plastic DIP
MAX242EJN
-40°C to +85°C
18 CERDIP
MAX248EQH
-40°C to +85°C
44 PLCC
MAX242MJN
-55°C to +125°C
18 CERDIP
MAX249CQH
0°C to +70°C
44 PLCC
MAX249EQH
-40°C to +85°C
44 PLCC
* Contact factory for dice specifications.
Package Information
For the latest package outline information, go to
www.maxim-ic.com/packages.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
36 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
ANEXO A.3 – MX7828
19-0255; Rev 2; 4/94
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
________________________Applications
Digital Signal Processing
High-Speed Data Acquisition
Telecommunications
High-Speed Servo Control
Audio Instrumentation
____________________________Features
♦ One-Chip Data Acquisition System
♦ Four or Eight Analog Input Channels
♦ 2.5µs per Channel Conversion Time
♦ Internal 2.5V Reference (MAX154/MAX158 only)
♦ Built-In Track/Hold Function
♦ 1/2LSB Error Specification
♦ Single +5V Supply Operation
♦ No External Clock
♦ New Space-Saving SSOP Package
______________Ordering Information
TEMP. RANGE
PART
PIN-PACKAGE
ERROR
(LSB)
MX7824LN
0°C to +70°C
24 Narrow
Plastic DIP
±1/2
MX7824KN
0°C to +70°C
24 Narrow
Plastic DIP
±1
MX7824LCWG
0°C to +70°C
24 Wide SO
±1/2
MX7824KCWG
0°C to +70°C
24 Wide SO
MX7824LCAG
0°C to +70°C
24 SSOP
MX7824KCAG
0°C to +70°C
24 SSOP
Ordering Information continued on last page.
±1
±1/2
±1
__________________________________________________________Pin Configurations
TOP VIEW
AIN4 1
24 VDD
AIN3 2
23 NC
AIN2 3
22 A0
AIN1 4
TP (REF OUT) 5
21 A1
MAX154
MX7824
20 DB7
AIN6 1
28 AIN7
AIN5 2
27 AIN8
AIN4 3
26 VDD
AIN3 4
25 A0
AIN2 5
AIN1 6
MAX158
MX7828
24 A1
23 A2
19 DB6
TP (REF OUT) 7
22 DB7
18 DB5
DB0 8
21 DB6
DB2 8
17 DB4
DB1 9
20 DB5
DB3 9
16 CS
DB2 10
19 DB4
RD 10
15 RDY
DB3 11
18 CS
INT 11
14 VREF+
RD 12
17 RDY
13 VREF-
INT 13
16 VREF+
GND 14
15 VREF-
DB0 6
DB1 7
GND 12
DIP/SO/SSOP
DIP/SO/SSOP
( ) ARE FOR MAX154/MAX158 ONLY.
________________________________________________________________ Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
1
MX7824/MX7828
_______________General Description
The MAX154/MAX158 and MX7824/MX7828 are highspeed, multi-channel analog-to-digital converters
(ADCs). The MAX154 and MX7824 have four analog
input channels, while the MAX158 and MX7828 have
eight channels. Conversion time for all devices is 2.5µs.
The MAX154/MAX158 also feature a 2.5V on-chip reference, forming a complete high-speed data acquisition
system.
All four converters include a built-in track/hold, eliminating the need for an external track/hold with many input
signals. The analog input range is 0V to +5V, although
the ADC operates from a single +5V supply.
Microprocessor interfaces are simplified by the ADC’s
ability to appear as a memory location or I/O port without
the need for external logic. The data outputs use latched,
three-state buffer circuitry to allow direct connection to a
microprocessor data bus or system input port.
The MX7824 and MX7828 are pin compatible with
Analog Devices’ AD7824 and AD7828. The MAX154
and MAX158, which feature internal references, are also
compatible with these products.
MX7824/MX7828
with Multiplexer
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VDD to GND ........................................0V, +10V
Voltage at Any Other Pins......................GND - 0.3V, VDD + 0.3V
Output Current (REF OUT)..................................................30mA
Power Dissipation (any package) to +75°C ....................450mW
Derate above +25°C by ..............................................6mW/°C
MX7824, MX7828
KN/LN/KCW_/LCW_ ............................................0°C to +70°C
BQ/CQ .............................................................-40°C to +85°C
TQ/UQ............................................................-55°C to +125°C
Lead Temperature (soldering, 10sec) .............................+300°C
ELECTRICAL CHARACTERISTICS
(VDD = +5V, VREF+ = +5V, VREF- = GND, Mode 0, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ACCURACY
Resolution
8
Bits
MAX15_A, MX782_L/C/U
MAX15_B, MX782_K/B/T
Total Unadjusted Error (Note 1)
No Missing Codes Resolution
±1/2
±1
LSB
±1/4
LSB
8
Bits
Channel to Channel Mismatch
REFERENCE INPUT
Reference Resistance
1
4
kΩ
VREF+ Input Voltage Range
VREF-
VDD
V
VREF- Input Voltage Range
GND
VREF+
V
REFERENCE OUTPUT—MAX154/MAX158 Only (Note 2)
Output Voltage
2.50
2.53
V
Load Regulation
REF OUT
IL = 0mA to 10mA, TA = +25°C
-6
-10
mV
Power-Supply Sensitivity
VDD ±5%, TA = +25°C
±1
±3
mV
MAX15_C
40
70
MAX15_E
40
70
MAX15_M
60
100
Temperature Drift (Note 3)
Output Noise
TA = +25°C
2.47
eN
200
Capacitive Load
ppm/°C
µV/rms
0.01
µF
ANALOG INPUT
Analog Input Voltage Range
AINR
Analog Input Capacitance
CAIN
Analog Input Current
IAIN
VREF-
VREF+
45
Any channel, AIN = 0V to 5V
Slew Rate, Tracking
SR
–—– –—–
LOGIC INPUTS ( RD , CS , A0, A1, A2)
0.7
V
pF
±3
µA
0.157
V/µs
Input High Voltage
VINH
Input Low Voltage
VINL
0.8
V
Input High Current
IINH
1
µA
Input Low Current
IINL
-1
µA
Input Capacitance (Note 4)
CIN
8
pF
2
2.4
V
5
_______________________________________________________________________________________
with Multiplexer
MX7824/MX7828
ELECTRICAL CHARACTERISTICS
PARAMETER
SYMBOL
CONDITIONS
MIN
VOH
—
–—–
DB0–DB7, INT; IOUT = -360µA
4.0
VOL
—
–—–
DB0–DB7, INT; RDY
TYP
MAX
UNITS
LOGIC OUTPUTS
Output High Voltage
Output Low Voltage
Three-State Output Current
Output Capacitance (Note 4)
V
IOUT = 1.6mA
0.4
IOUT = 2.6mA
0.4
DB0–DB7, RDY; VOUT = 0V to VDD
COUT
5
V
±3
µA
8
pF
POWER SUPPLY
Supply Voltage
VDD
Supply Current
IDD
5V ±5% for specified performance
–—– –—–
CS = RD = 2.4V
PSS
VDD = ±5%
4.75
Power Dissipation
Power-Supply Sensitivity
Note 1:
Note 2:
Note 3:
Note 4:
5.25
V
15
mA
25
75
mW
±1/16
±1/4
LSB
Total unadjusted error includes offset, full-scale, and linearity errors.
Specified with no external load unless otherwise noted.
Temperature drift is defined as change in output voltage from +25°C to TMIN or TMAX divided by (25 - TMIN) or (TMAX - 25).
Guaranteed by design.
TIMING CHARACTERISTICS (Note 5)
PARAMETER
SYMBOL
TA = +25°C
CONDITIONS
MIN
–—– –—–
CS to RD Setup Time
–—– –—–
CS to RD Hold Time
Multiplexer Address
Setup Time
Multiplexer Address
Hold Time
–—–
CS to RDY Delay
Conversion Time (Mode 0)
–—–
Data Access Time After RD
Data Access Time
—
–—–
After INT, Mode 0
–—– —
–—–
RD to INT Delay (Mode 1)
Data Hold Time
Delay Time
Between Conversions
–—–
RD Pulse Width (Mode 1)
TYP
MAX
MAX15_ _C/E
MX782_K/L/B/C
MIN
MAX
MAX15_ _M
MX782_T/U
MIN
UNITS
MAX
tCSS
0
0
0
ns
tCSH
0
0
0
ns
tAS
0
0
0
ns
30
tAH
40
ns
40
2.0
85
60
2.4
110
60
2.8
120
ns
µs
ns
(Note 6)
20
50
60
70
ns
CL = 50pF
40
75
100
100
ns
60
70
70
ns
CL = 50pF, RL = 5kΩ
tACC2
tINTH
tDH
35
30
1.6
tRDY
tCRD
tACC1
(Note 6)
(Note 7)
tP
500
tRD
60
500
600
80
600
500
80
ns
400
ns
Note 5: All input control signals are specified with tR = tF = 20ns (10% to 90% of +5V) and timed from a 1.6V voltage level.
Note 6: Measured with load circuits of Figure 1 and defined as the time required for an output to cross 0.8V or 2.4V.
Note 7: Defined as the time required for the data lines to change 0.5V when loaded with the circuits of Figure 2.
_______________________________________________________________________________________
3
(TA = +25°C, unless otherwise noted.)
OUTPUT CURRENT
vs. TEMPERATURE
VDD = 5V
2.500
2.490
LINEARITY ERROR (LSB)
16
OUTPUT CURRENT (mA)
2.510
2.0
MX7824/28-2
20
MX7824/28-1
2.520
ACCURACY vs. DELAY BETWEEN
CONVERSIONS (tp)
ISOURCE VOUT = 2.4V
12
8
ISINK VOUT = 0.4V
4
0
50
-100
150
100
0.5
-50
0
50
300
150
100
400
500
ACCURACY vs. VREF
(VREF = VREF+ - VREF-)
600
700
8
IDD – SUPPLY CURRENT (mA)
MX7824/28-4
VDD = 5V
1.5
1.0
0.5
0
7
VDD = 5.25V
6
5
VDD = 5V
4
VDD = 4.75V
3
2
0
1
2
3
4
5
-100
VREF (V)
-50
0
50
100
150
AMBIENT TEMPERATURE (°C)
+5V
+5V
3k
DBN
DBN
100pF
100pF
DGND
DGND
b. High-Z to VOL
Figure 1. Load Circuits for Data-Access Time Test
4
3k
DBN
DBN
a. High-Z to VOH
900
POWER-SUPPLY CURRENT vs. TEMPERATURE
(NOT INCLUDING REFERENCE LADDER)
2.0
3k
800
tp (ns)
LINEARITY ERROR (LSB)
1.0
MX7824/28-5
-50
VDD = 5V
VREF = 5V
1.5
0
0
2.480
MX7824/28-3
REFERENCE TEMPERATURE
DRIFT (MAX154/MAX158 ONLY)
REF OUT VOLTAGE (V)
MX7824/MX7828
with Multiplexer
3k
10pF
10pF
DGND
a. VOH to High-Z
DGND
b. VOL to High-Z
Figure 2. Load Circuits for Data-Hold Time Test
_______________________________________________________________________________________
with Multiplexer
PIN
PIN
NAME
FUNCTION
MAX154
MX7824
NAME
FUNCTION
MAX158
MX7828
1
AIN4
Analog Input Channel 4
1
AIN6
2
AIN3
2
AIN5
3
AIN2
3
AIN4
4
AIN1
4
AIN3
5
REF OUT
TP
Reference Output (2.5V) for MAX154.
Test point for MX7824. Do not connect.
5
AIN2
6
AIN1
6
DBO
Three-State Data Output, bit 0 (LSB)
7
DB1
Three-State Data Output, bit 1
7
REF OUT
TP
8
DB2
8
DB0
Three-State Data Output, bit 0 (LSB)
9
DB3
–—–
Read Input. RD controls conversions
and data access. See Digital Interface
section.
Interrupt Output. INT going low indicates the completion of a conversion.
See Digital Interface section.
9
DB1
10
DB2
11
DB3
12
–—–
RD
–—–
Read Input. RD controls conversions
and data access. See Digital Interface
section.
Ground
Lower Limit of Reference Span. Sets
the zero-code voltage.
Range: GND to VREF+.
Upper Limit of Reference Span. Sets
the full-scale input voltage.
Range: VREF- to VDD.
13
INT
Interrupt Output. INT going low indicates the completion of a conversion.
See Digital Interface section.
14
GND
15
VREF-
Ready Output. Open-drain output with
no active pull-up device. Goes low
–—–
when CS goes low and high impedance at the end of a conversion.
–—–
Chip-Select Input. CS must be low for
the device to be selected.
16
VREF+
17
RDY
18
–—–
CS
10
–—–
RD
11
INT
12
GND
13
VREF-
14
VREF+
15
RDY
Reference Output (2.5V) for MAX158.
Test point for MX7828. Do not connect.
Ground
Lower Limit of Reference Span. Sets
the zero-code voltage.
Range: GND to VREF+.
Upper Limit of Reference Span. Sets
the full-scale input voltage.
Range: VREF- to VDD.
Ready Output. Open-drain output with
no active pull-up device. Goes low
–—–
when CS goes low and high impedance at the end of a conversion.
–—–
Chip-Select Input. CS must be low for
the device to be selected.
16
–—–
CS
17
DB4
18
DB5
19
DB6
19
DB4
20
DB7
Three-State Data Output, bit 7 (MSB)
20
DB5
21
A1
Channel Address 1 Input
21
DB6
22
A0
22
DB7
Three-State Data Output, bit 7 (MSB)
23
NC
No Connect
23
A2
24
VDD
Power-Supply Voltage, +5V
24
A1
25
A0
26
VDD
Power-Supply Voltage, +5V
27
AIN8
28
AIN7
_______________________________________________________________________________________
5
MX7824/MX7828
_____________________________________________________________Pin Descriptions
MX7824/MX7828
with Multiplexer
_______________Detailed Description
___________________Digital Interface
Converter Operation
The MAX154/MAX158 and MX7824/MX7828 use only
Chip Select (CS) and Read (RD) as control inputs. A
READ operation, taking CS and RD low, latches the multiplexer address inputs and starts a conversion (Table 1).
The MAX154/MAX158 and MX7824/MX7828 use what is
commonly called a “half-flash” conversion technique
(Figure 3). Two 4-bit flash ADC sections are used to
achieve an 8-bit result. Using 15 comparators, the
upper 4-bit MS (most significant) flash ADC compares
the unknown input voltage to the reference ladder and
provides the upper four data bits.
An internal DAC uses the MS bits to generate an analog
signal from the first flash conversion. A residue voltage
representing the difference between the unknown input
and the DAC voltage is then compared to the reference
ladder by 15 LS (least significant) flash comparators to
obtain the lower four output bits.
Table 1. Truth Table for Input Channel
Selection
MAX154/MX7824
A1
A0
0
0
1
1
0
1
0
1
Operating Sequence
The operating sequence is shown in Figure 4. A conversion is initiated by a falling edge of RD and CS. The
comparator inputs track the analog input voltage for
approximately 1µs. After this first cycle, the MS flash
result is latched into the output buffers and the LS conversion begins. INT goes low approximately 600ns
later, indicating the end of the conversion, and that the
lower four bits are latched into the output buffers. The
data can then be accessed using the CS and RD
inputs.
AIN1
REF OUT**
0
0
0
0
0
0
1
1
0
1
0
1
AIN1
AIN2
AIN3
AIN4
1
1
1
1
0
0
1
1
0
1
0
1
AIN5
AIN6
AIN7
AIN8
DB7
DB6
4-BIT
FLASH
ADC
(4MSB)
VREF-
VREF+
16
2.5V
REF
*MAX154/MX7824 – 4-Channel Mux
MAX158/MX7828 – 8-Channel Mux
** REF OUT on MAX154/MAX158 only
DB5
DB4
THREESTATE
DRIVERS
4-BIT
DAC
MUX*
AIN8
A1
A2
DB3
DB2
DB1
4-BIT
FLASH
ADC
(4LSB)
ADDRESS
LATCH
DECODE
A0
DB0
TIMING AND CONTROL
CIRCUITRY
RDY
CS
INT
RD
Figure 3. Functional Diagram
6
SELECTED
CHANNEL
There are two interface modes, which are determined
by the length of the RD input. Mode 0, implemented by
keeping RD low until the conversion ends, is designed
for microprocessors that can be forced into a WAIT
state. In this mode, a conversion is started with a READ
operation (taking CS and RD low), and data is read
when the conversion ends. Mode 1, on the other hand,
VREF+
AIN4
MAX158/MX7828
A2
A1
A0
_______________________________________________________________________________________
with Multiplexer
500ns
1000ns
SETUP TIME REQUIRED
BY THE INTERNAL
COMPARATORS PRIOR TO
STARTING CONVERSION
600ns
VIN IS SAMPLED
AND THE FOUR MSBs
ARE LATCHED
VIN IS TRACKED
BY INTERNAL
COMPARATORS
There are two status outputs: Interrupt (INT) and Ready
(RDY). RDY, an open-drain output (no internal pull-up
device), is connected to the processor’s READY/WAIT
input. RDY goes low on the falling edge of CS and goes
high impedance at the end of the conversion, when the
conversion result appears on the data outputs. If the RDY
output is not required, its external pull-up resistor can be
omitted. INT goes low when the conversion is complete
and returns high on the rising edge of CS or RD.
Interface Mode 1
Figure 4. Operating Sequence
does not require microprocessor WAIT states. A READ
operation simultaneously initiates a conversion and
reads the previous conversion result.
Interface Mode 0
Figure 5 shows the timing diagram for Mode 0 operation. This is used with microprocessors that have WAIT
state capability, whereby a READ instruction is extended to accommodate slow-memory devices. Taking CS
and RD low latches the analog multiplexer address and
starts a conversion. Data outputs DB0–DB7 remain in
the high-impedance condition until the conversion is
complete.
Mode 1 is designed for applications where the microprocessor is not forced into a WAIT state. Taking CS
and RD low latches the multiplexer address and starts
a conversion (Figure 6). Data from the previous conversion is immediately read from the outputs (DB0–DB7).
INT goes high at the rising edge of CS or RD and goes
low at the end of the conversion. A second READ operation is required to read the result of this conversion.
The second READ latches a new multiplexer address
and starts another conversion. A delay of 2.5µs must
be allowed between READ operations. RDY goes low
on the falling edge of CS and goes high impedance at
the rising edge of CS. If RDY is not needed, its external
pull-up resistor can be omitted.
CS
tCSH
tCSS
tCSS
RD
tP
tAS
tAS
ANALOG
CHANNEL
ADDRESS
ADDR
VALID
ADDR
VALID
tAH
RDY
tRDY
INT
tINTH
tCRD
tACC2
HIGH IMPEDANCE
DATA
tDH
DATA
VALID
Figure 5. Mode 0 Timing Diagram
_______________________________________________________________________________________
7
MX7824/MX7828
RD
INT GOING LOW
INDICATES THAT
CONVERSION IS
COMPLETE AND
THAT DATA CAN
BE READ
MX7824/MX7828
with Multiplexer
CS
tRD
tCSS
tCSH
tCSS
tCSH
tRD
RD
tP
tAS
tAS
ANALOG
CHANNEL
ADDRESS
ADDR
VALID
ADDR
VALID
tAH
tAH
RDY
tRDY
tRDY
tCRD
tINTH
INT
tACCI
tINTH
tDH
tDH
tACCI
OLD
DATA
DATA
NEW
DATA
Figure 6. Mode 1 Timing Diagram
_____________Analog Considerations
OUTPUT
CODE
Reference and Input
The VREF+ and VREF- inputs of the converter define the
zero and the full-scale of the ADC. In other words, the
voltage at VREF- is equal to the input voltage that produces an output code of all zeros, and the voltage at
VREF+ is equal to input voltage that produces an output
code of all ones (Figure 7).
Figure 8 shows some possible reference configurations. For the MAX154/MAX158, a 0.01µF bypass
capacitor to GND should be used to reduce the highfrequency output impedance of the internal reference.
Larger capacitors should not be used, as this degrades
the stability of the reference buffer. The 2.5V reference
output is with respect to the GND pin.
FULL-SCALE
TRANSITION
11111111
11111110
11111101
1LSB = F8 = VREF+ - VREF256
256
00000011
00000010
VREF+
00000001
Bypassing
A 47µF electrolytic and 0.1µF ceramic capacitor should
be used to bypass the VDD pin to GND. These capacitors must have minimum lead length, since excess lead
length may contribute to conversion errors and instability.
If the reference inputs are driven by long lines, they
should be bypassed to GND with 0.1µF capacitors at
the reference input pins.
8
00000000
VREF-
1
2
3
FS
AIN INPUT VOLTAGE
(IN TERMS OF LSBs)
Figure 7. Transfer Function
_______________________________________________________________________________________
FS–1LSB
with Multiplexer
VIN
AINx(-)
GND
VDD
+5V
REF OUT
0.1µF
47µF
Input Current
MAX154
MAX158
VREF+
0.01µF
VREF-
Figure 8a. Internal Reference (MAX154/MAX158 only)
AINx(+)
VIN
AINx(-)
GND
VDD
+5V
0.1µF
2.5V
47µF
MX584
MX7824
MX7828
VREF+
VREF-
Figure 8b. External Reference +2.5V Full-Scale
AINx(+)
VIN
AINx(-)
GND
Input Filtering
MAX154
MAX158
VREF+ MX7824
MX7828
VDD
+5V
0.1µF
47µF
The converters’ analog inputs behave somewhat differently from conventional ADCs. The sampled data comparators take varying amounts of current from the input,
depending on the cycle they are in. The equivalent circuit of the converter is shown in Figure 9a. When the
conversion starts, AIN(n) is connected to the MS and
LS comparators. Thus, AIN(n) is connected to thirty-one
1pF capacitors.
To acquire the input signal in approximately 1µs, the
input capacitors must charge to the input voltage
through the on-resistance of the multiplexer (about
600Ω) and the comparator’s analog switches (2kΩ to
5kΩ per comparator). In addition, about 12pF of stray
capacitance must be charged. The input can be modeled as an equivalent RC network shown in Figure 9b.
As RS (source impedance) increases, the capacitors
take longer to charge.
Since the length of the input acquisition time is internally set, large source resistances (greater than 100Ω) will
cause settling errors. The output impedance of an opamp is its open-loop output impedance divided by the
loop gain at the frequency of interest. It is important
that the amplifier driving the converter input have sufficient loop gain at approximately 1MHz to maintain low
output impedance.
VREF-
Figure 8c. Power Supply as Reference
The transients in the analog input caused by the sampled data comparators do not degrade the converter’s
performance, since the ADC does not “look” at the
input when these transients occur. The comparator’s
outputs track the input during the first 1µs of the conversion, and are then latched. Therefore, at least 1µs
will be provided to charge the ADC’s input capacitance. It is not necessary to filter these transients with
an external capacitor on the AIN terminals.
Sinusoidal Inputs
* Current path must
still exist from
VIN(-) to Ground
AINx(+)
VIN
GND
VDD
+5V
0.1µF
VREF+
47µF
2.5V
VREF-
AINx(-)
*
MAX154
MAX158
MX7824
MX7828
The MAX154/MAX158 and MX7824/MX7828 can measure input signals with slew rates as high as 157mV/µs
to the rated specifications. This means that the analog
input frequency can be as high as 10kHz without the
aid of an external track/hold. The maximum sampling
rate is limited by the conversion time (typical tCRD =
2µs) plus the time required between conversions (tp =
500ns). It is calculated as:
fMAX =
1
1
=
= 400kHz
tCRD + tp
(2.0 + 0.5) µs
Figure 8d. Inputs Not Referenced to GND
_______________________________________________________________________________________
9
MX7824/MX7828
AINx(+)
MX7824/MX7828
with Multiplexer
fMAX permits a maximum sampling rate of 50kHz per
channel when using the MAX158/MX7828 and 100kHz
per channel when using the MAX154/MX7824. These
rates are well above the Nyquist requirement of 20kHz
sampling rate for a 10kHz input bandwidth.
Bipolar Input Operation
The circuit in Figure 10a can be used for bipolar input
operation. The input voltage is scaled by an amplifier so
that only positive voltages appear at the ADC’s inputs.
An external reference should be used for the MX7824/
MX7828, but is not needed with the MAX154/MAX158.
The analog input range is ±4V and the output code is
complementary offset binary. The ideal input/output
characteristic is shown in Figure 10b.
3.57k
11.5Ω
VIN
0.01µF
CS
AIN1
10.0k
MAX154
MAX158
16.2k
RDY
RD
0.01µF
VREF+
INT
REF OUT
+5V
VDD
DB0–DB7
VREF47µF
0.1µF
RS
AIN1
VIN
CS
2pF
RON
RMUX
CS
12pF
GND
ONLY CHANNEL 1 SHOWN
1pF
1pF
•
•
•
15 LSB COMPARATORS
TO LS
LADDER
Figure 10a. Bipolar ±4V Input Operation
RON
1pF
1pF
•
•
•
16 MSB COMPARATORS
TO MS
LADDER
FS = 8V
1LSB = FS / 256
11111111
11111110
11111101
Figure 9a. Equivalent Input Circuit
10000010
10000001
+FS
2
10000000
01111111
RS
VIN
AIN1
B MUX
600Ω
CS1
2pF
01111110
RON
350Ω
CS2
2pF
-FS + 1LSB
2
00000010
00000001
32pF
00000000
0V
AIN INPUT VOLTAGE (LSBs)
Figure 9b. RC Network Model
10
Figure 10b. Transfer Function for ±4V Input Operation
______________________________________________________________________________________
with Multiplexer
ADDRESS BUS
VDD
A0
EN
MREQ
ADDRESS
DECODE
A0
A1
A2*
BANDPASS
FILTER 1
6
BANDPASS
FILTER 2
5 AIN2
AIN1
5V
ZBO
MX7824/MX7828
+5V
26
A15
MAX154
MAX158
RDY MX7824
MX7828
RD
CS
5k
WAIT
RD
18
RD
12
MAX158
MX7828
AMP
DB0–DB7
BANDPASS
FILTER 7
28
A2
BANDPASS
FILTER 8
+5V
DATA
AIN7
DB0–DB7
DATA BUS
D0–D7
SPEECH
INPUT
CS
27 AIN8
16
VREF+
VREF15
A1
A0
23
24
25
GND
14
*A2 ON MAX158/MX7828 ONLY.
Figure 12. Speech Analysis Using Real-Time Filtering
Figure 11. Simple Mode 0 Interface
SAMPLE
PULSE
+5V
24
VDD
16
CS
4 AIN1
3 AIN2
2
1
14
13
12
AIN3
AIN4
+15V
18
VDD
10
RD
INT
11
15
VREF 4
WR
MAX154
MX7824
VOUT A 2
MX7226
DB0–DB7
VOUT B 1
VOUT C
DB0–DB7
VREF+
VOUT D
VREF-
A1
A0
GND
21
16
A1
22
17
A0
DGND
AGND
20
19
6
5
VSS
3
A0
A1
Figure 13. 4-Channel Fast Sample and Infinite Hold
______________________________________________________________________________________
11
MX7824/MX7828
with Multiplexer
_Ordering Information (continued)
PART
TEMP. RANGE
PIN-PACKAGE
MX7824LEAG
-40°C to +85°C
24 SSOP
ERROR
(LSB)
MX7824KEAG
-40°C to +85°C
24 SSOP
-40°C to +85°C
24 CERDIP
±1/2
MX7824BQ
MX7824UQ
MX7824TQ
-40°C to +85°C
-55°C to +125°C
-55°C to +125°C
24 CERDIP
24 CERDIP
24 CERDIP
±1
±1/2
±1
MX7828LN
MX7828KN
MX7828LCWI
0°C to +70°C
0°C to +70°C
0°C to +70°C
28 Plastic DIP
28 Plastic DIP
28 Wide SO
±1/2
±1
±1/2
MX7828KCWI
0°C to +70°C
28 Wide SO
MX7828LCAI
0°C to +70°C
28 SSOP
±1/2
MX7828KCAI
0°C to +70°C
28 SSOP
±1
MX7828LP
0°C to +70°C
28 PLCC
±1/2
0°C to +70°C
28 PLCC
±1
-40°C to +85°C
28 SSOP
±1/2
MX7828KP
AIN4 AIN6 AIN8
(N.C.) (AIN2) (AIN4)
AIN3 AIN5 AIN7
(N.C.) (AIN1) (AIN3)
±1/2
MX7824CQ
MX7828LEAI
___________________Chip Topography
VDD A0
±1
±1
MX7828KEAI
-40°C to +85°C
28 SSOP
MX7828CQ
-40°C to +85°C
28 CERDIP
±1/2
±1
MX7828BQ
-40°C to +85°C
28 CERDIP
±1
MX7828UQ
-55°C to +125°C
28 CERDIP
±1/2
MX7828TQ
-55°C to +125°C
28 CERDIP
±1
A1
A2 (N.C.)
AIN2 (N.C.)
AIN1 (N.C.)
TP (REF OUT)
0.127"
(3.228mm)
DB7
DB0
DB6
DB1
DB5
DB2
DB4
DB3
CS
A0
GND VREF+
INT VREF-
ADY
0.124"
(3.150mm)
( ) ARE FOR MAX154/MX7824
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 1995 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
ANEXO A.4 – SAA1042
Order this document by SAA1042/D
The SAA1042 drives a two–phase stepper motor in the bipolar mode. The
device contains three input stages, a logic section and two output stages.
The IC is contained in a 16 pin dual–in–line heat tab plastic package for
improved heatsinking capability. The center four ground pins are connected
to the copper alloy heat tab and improve thermal conduction from the die to
the circuit board.
• Drive Stages Designed for Motors: 6.0 V and 12 V: SAA1042V
•
•
•
•
•
•
•
STEPPER MOTOR
DRIVER
SEMICONDUCTOR
TECHNICAL DATA
500 mA/Coil Drive Capability
Built–In Clamp Diodes for Overvoltage Suppression
Wide Logic Supply Voltage Range
Accepts Commands for CW/CCW and Half/Full Step Operation
Inputs Compatible with Popular Logic Families: MOS, TTL, DTL
Set Input Defined Output State
Drive Stage Bias Adaptable to Motor Power Dissipation for
Optimum Efficiency
16
1
V SUFFIX
PLASTIC PACKAGE
CASE 648C
PIN CONNECTIONS
L2
1
16 L3
VD
2
15 VM
L1
3
14 L4
4
13
5
12
Set/
Driver Bias
Clock
6
11 VCC
7
10 CW/CCW
Full/Half
Step
8
9
Figure 1. Representative Block Diagram
VZ
VCC
VM
15
11
Gnd
VD
2
3
7
L1
Clock
Driver
M
1
10
CW/CCW
L2
Gnd
Gnd
(Top View)
Logic
16
L3
8
Full/
Half Step
Driver
14
L4
ORDERING INFORMATION
9
Gnd
6
Driver Bias
RB
Set
Device
Operating
Temperature Range
Package
SAA1042V
TJ = – 30° to +125°C
Plastic DIP
A
 Motorola, Inc. 1996
MOTOROLA ANALOG IC DEVICE DATA
Rev 2
1
SAA1042
MAXIMUM RATINGS (TA = 25°C, unless otherwise noted.)
Symbol
SAA1042V
Unit
Clamping Voltage (Pins 1, 3, 14, 16)
Rating
Vclamp
20
V
Over Voltage (VOV = Vclamp – VM)
VOV
6.0
V
Supply Voltage
VCC
20
V
Switching or Motor Current/Coil
Input Voltage (Pins 7, 8, 10)
IM
500
mA
Vin clock
Vin Full/Half
Vin CW/CCW
VCC
V
PD
θJA
θJC
2.0
80
15
W
°C/W
TJ
–30 to +125
°C
Tstg
–65 to +150
°C
Power Dissipation (Note 1)
Thermal Resistance, Junction–to–Air
Thermal Resistance, Junction–to–Case
Operating Junction Temperature Range
Storage Temperature Range
NOTE:
1. The power dissipation (PD) of the circuit is given by the supply voltage (VM and VCC) and the
motor current (IM), and can be determined from Figures 3 and 5. PD = Pdrive – Plogic.
ELECTRICAL CHARACTERISTICS (TA = 25°C, unless otherwise noted.)
Characteristics
Pin(s)
Symbol
VCC
Min
Typ
Max
Unit
Supply Current
11
ICC
5.0 V
20 V
—
—
—
—
3.5
8.5
mA
Motor Supply Current
(IPin 6 = –400 µA, Pins 1, 3, 14, 16 Open)
VM = 6.0 V
VM = 12 V
VM = 24 V
15
IM
Input Voltage, High State
7, 8, 10
Input Voltage, Low State
Input Reverse Current, High State
(Vin = VCC)
7, 8, 10
Input Forward Current, Low State
(Vin = Gnd)
mA
5.0 V
5.0 V
5.0 V
—
—
—
25
30
40
—
—
—
VIH
5.0 V
10 V
15 V
20 V
2.0
7.0
10
14
—
—
—
—
—
—
—
—
VIL
5.0 V
10 V
15 V
20 V
—
—
—
—
—
—
—
—
0.8
1.5
2.5
3.5
IIR
5.0 V
10 V
15 V
20 V
—
—
—
—
—
—
—
—
2.0
2.0
3.0
5.0
IIF
5.0 V
10 V
15 V
20 V
–10
–25
–40
–50
—
—
—
—
—
—
—
—
VOH
5.0 –
20 V
—
—
VM – 2.0
VM – 1.2
—
—
—
—
0.7
0.2
—
—
V
µA
Output Voltage, High State (VM = 12 V)
Iout = –500 mA
Iout = –50 mA
Output Voltage, Low State
Iout = 500 mA
Iout = 50 mA
1, 3, 14, 16
Output Leakage Current, Pin 6 = Open
(VM = VD = Vclamp max)
1, 3, 14, 16
IDR
5.0 –
20 V
–100
—
—
µA
Clamp Diode Forward Voltage (Drop at IM = 500 mA)
2
—
—
2.5
3.5
V
Clock Frequency
7
VF
fc
5.0 –
20 V
0
—
50
kHz
Clock Pulse Width
7
tw
5.0 –
20 V
10
—
—
µs
Set Pulse Width
6
ts
—
10
—
—
µs
Set Control Voltage, High State
Set Control Voltage, Low State
6
—
—
VM
—
—
—
—
0.5
V
2
VOL
5.0 –
20 V
V
SAA1042
INPUT/OUTPUT FUNCTIONS
Clock — (Pin 7) This input is active on the positive edge of
the clock pulse and accepts Logic ‘1’ input levels dependent
on the supply voltage and includes hysteresis for noise
immunity.
CW/CCW — (Pin 10) This input determines the motor’s
rotational direction. When the input is held low, (OV, see the
electrical characteristics) the motor’s direction is nominally
clockwise (CW). When the input is in the high state, Logic ‘1’,
the motor direction is nominally counter clockwise (CCW),
depending on the motor connections.
Full/Half Step — (Pin 8) This input determines the angular
rotation of the motor for each clock pulse. In the low state, the
motor will make a full step for each applied clock pulse, while
in the high state, the motor will make half a step.
VD — (Pin 2) This pin is used to protect the outputs (1, 3,14,
16) where large positive spikes occur due to switching the
motor coils. The maximum allowable voltage on these pins is
the clamp voltage (Vclamp). Motor performance is improved if
a zener diode is connected between Pin 2 and 15, as shown
in Figure 1.
The following conditions have to be considered when
selecting the zener diode:
Vclamp = VM + 6.0 V
VZ = Vclamp – VM – VF
where:
VF = clamp diodes forward voltage drop
VF = (see Figure 4)
Vclamp: ≤ 20 V for SAA1042V ≤ 30 V for
Vclamp: SAA1042AV
Pins 2 and 15 can be linked, in this case VZ = 0 V.
Set/Bias Input — (Pin 6) This input has two functions:
1) The resistor RB adapts the drivers to the motor current.
2) A pulse via the resistor RB sets the outputs (1, 3, 14, 16) to
a defined state.
The resistor RB can be determined from the graph of
Figure 2 according to the motor current and voltage. Smaller
values of RB will increase the power dissipation of the circuit
and larger values of RB may increase the saturation voltage
of the driver transistors.
When the “set” function is not used, terminal A of the
resistor RB must be grounded. When the set function is used,
terminal A has to be connected to an open–collector (buffer)
circuit. Figure 7 shows this configuration. The buffer circuit
(off–state) has to sustain the motor voltage (VM). When a
pulse is applied via the buffer and the bias resistor (RB), the
motor driver transistors are turned off during the pulse and
after the pulse has ended, the outputs will be in defined
states. Figure 6 shows the Timing Diagram.
Figure 7 illustrates a typical application in which the
SAA1042 drives a 12 V stepper motor with a current
consumption of 200 mA/coil. A bias resistor (RB) of 56 kΩ is
chosen according to Figure 2.
The maximum voltage permitted at the output pin is
VM + 6.0 V (see Maximum Ratings table), in this application
VM = 12 V, therefore the maximum voltage is 18 V. The
outputs are protected by the internal diodes and an external
zener connected between Pins 2 and 15.
From Figure 4, it can be seen that the voltage drop across
the internal diodes is about 1.7 V at 200 mA. This results in a
zener voltage between Pins 2 and 15 of:
VZ = 6.0 V – 1.7 V = 4.3 V.
To allow for production tolerances and a safety margin, a
3.9 V zener has been chosen for this example.
The clock is derived from the line frequency which is
phase–locked by the MC14046B and the MC14024. The
voltage on the clock input is normally low (Logic ‘0’). The
motor steps on the positive going transition of the clock pulse.
The Logic ‘0’ applied to the Full/Half input (Pin 8) operates
the motor in Full Step mode. A Logic ‘1’ at this input will result
in Half Step mode. The logic level state on the CW/CCW
input (Pin 10), and the connection of the motor coils to the
outputs determines the rotational direction of the motor.
These two inputs should be biased to a Logic ‘0’ or ‘1’ and
not left floating. In the event of non–use, they should be tied
to ground or the logic supply line, VCC.
The output drivers can be set to a fixed operating point by
use of the Set input and a bias resistor, RB. A positive pulse
to this input turns the drivers off and sets the logic state of the
outputs.
After the negative going transition of the Set pulse, and
until the first positive going transition of the clock, the outputs
will be:
L1 = L3 = high and L2 = L4 = low, (see Figure 6).
The Set input can be driven by a MC14007B or a transistor
whose collector resistor is RB. If the input is not used, the
bottom of RB must be grounded.
The total power dissipation of the circuit can be
determined from Figures 3 and 5:
PD = 0.9 W + 0.08 W = 0.98 W.
The junction temperature can then be computed using
Figure 8.
3
SAA1042
Figure 2. Bias Resistor RB versus Motor Current
Figure 3. Drive Stage Power Dissipation
500
DRIVE STAGE POWER DISSIPATION (W)
R B BIAS RESISTOR (k Ω )
300
200
VM = 12 V
100
70
VM = 24 V
50
VM = 6.0 V
30
20
10
0
20
30 40 50 60
80 100
200
5.0
4.0
3.0
VM = 24 V
VM = 12 V
VM = 6.0 V
2.0
1.0
0.7
0.5
0.3
0.2
0.1
300 400 500
20
0
MOTOR CURRENT/COIL (mA)
Figure 4. Clamp Diode Forward Current
versus Forward Voltage
30
50 70 100
200
MOTOR CURRENT/COIL (mA)
300 400 500
Figure 5. Power Dissipation versus
Logic Supply Voltage
500
500
PD , POWER DISSIPATION (mV)
FORWARD CURRENT (mA)
300
400
200
300
100
200
100
70
50
30
20
10
0
0
1.0
2.0
3.0
4.0
5.0
0
5.0
VF , FORWARD VOLTAGE (V)
10
15
20
25
VCC , SUPPLY VOLTAGE (V)
Figure 6. Timing Diagram
Full Step Motor Drive Mode. Full/Half Step Input = 0
Clock
Set
CW/CCW
L1
L2
L3
L4
Don’t Care
High Output Impedance
Half Step Motor Drive Mode. Full/Half Step Input = 1
Clock
Set
CW/CCW
L1
L2
L3
L4
4
SAA1042
Figure 7. Typical Application
Selectable Step Rates with the Time Base Derived from the Line Frequency
220 k
14
16
MC14046B
14
50 Hz
0.1 µF
Phase
Comp
1 5
4
VCO
2
3
9
11 6
MC14024
15
220 V
1
7
3
2
4.7 nF
Steps/Sec
12.5
100
9
200
7 12
11 15
8
Full
Half
25
4
5
6
11
82 k
8.2 µF
12 V 12 V
VZ = 3.9 V
12 V
50
Clock
7
SAA1042
12 V
2
3
1
M
16
400
CW
CCW
800
10
9
120 k
14
6
RB
56 k
f0 = 1400 Hz
Set Input
3
Set
5
MC14007
100
5.0
JUNCTION–TO–AIR (° C/W)
R θJA , THERMAL RESISTANCE
Printed circuit board heatsink example
80
L
RθJA
60
4.0
2.0 oz
Copper
L
3.0 mm
Graph represents symmetrical layout
3.0
40
2.0
1.0
PD(max) for TA = 70°C
20
0
0
10
30
20
L, LENGTH OF COPPER (mm)
40
50
0
PD(max), MAXIMUM POWER DISSIPATION (W)
Figure 8. Thermal Resistance and Maximum Power
Dissipation versus P.C.B. Copper Length
5
SAA1042
OUTLINE DIMENSIONS
V SUFFIX
PLASTIC PACKAGE
CASE 648C–03
ISSUE C
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.
4. DIMENSION B DOES NOT INCLUDE MOLD FLASH.
5. INTERNAL LEAD CONNECTION BETWEEN 4 AND
5, 12 AND 13.
–A–
16
9
1
8
–B–
L
NOTE 5
C
–T–
M
N
SEATING
PLANE
F
E
J
G
D 16 PL
0.13 (0.005)
16 PL
0.13 (0.005)
T A
M
M
T B
DIM
A
B
C
D
E
F
G
J
K
L
M
N
INCHES
MIN
MAX
0.740
0.840
0.240
0.260
0.145
0.185
0.015
0.021
0.050 BSC
0.040
0.70
0.100 BSC
0.008
0.015
0.115
0.135
0.300 BSC
0_
10_
0.015
0.040
MILLIMETERS
MIN
MAX
18.80
21.34
6.10
6.60
3.69
4.69
0.38
0.53
1.27 BSC
1.02
1.78
2.54 BSC
0.20
0.38
2.92
3.43
7.62 BSC
0_
10_
0.39
1.01
S
S
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals”
must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of
others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other
applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury
or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola
and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that
Motorola was negligent regarding the design or manufacture of the part. Motorola and
are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
Opportunity/Affirmative Action Employer.
How to reach us:
USA / EUROPE / Locations Not Listed: Motorola Literature Distribution;
P.O. Box 20912; Phoenix, Arizona 85036. 1–800–441–2447 or 602–303–5454
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51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298
6
◊
*SAA1042/D*
MOTOROLA ANALOG IC DEVICE
DATA
SAA1042/D
ANEXO A.5 – 7805
LM78XX (KA78XX, MC78XX) FIXED VOLTAGE REGULATOR (POSITIVE)
3-TERMINAL 1A POSITIVE
VOLTAGE REGULATORS
TO-220
The LM78XX series of three-terminal positive regulators are available in
the TO-220/D-PAK package and with several fixed output voltages, making
them useful in a wide range of applications. Each type employs internal
current limiting, thermal shut-down and safe area protection, making it
essentially indestructible. If adequate heat sinking is provided, they can
deliver over 1A output current. Although designed primarily as fixed voltage
regulators, these devices can be used with external components to obtain
adjustable voltages and currents.
D-PAK
1
FEATURES
•
•
•
•
•
1: Input 2: GND 3: Output
Output Current up to 1A
Output Voltages of 5, 6, 8, 9, 10, 11, 12, 15, 18, 24V
Thermal Overload Protection
Short Circuit Protection
Output Transistor SOA Protection
ORDERING INFORMATION
Device
Output Voltage
Tolerance
KA78XXCT
± 4%
KA78XXAT
± 2%
KA78XXIT
KA78XXR
Packag
e
TO-220
± 2%
KA78XXIR
± 4%
0 ~ +125 °C
-40 ~ +125 °C
± 4%
KA78XXAR
Operating Temperature
D-PAK
0 ~ +125 °C
-40 ~ +125 °C
BLOCK DIAGRAM
Rev. B
1999 Fairchild Semiconductor Corporation
ABSOLUTE MAXIMUM RATINGS (TA = +25°C, unless otherwise specified)
Characteristic
Symbol
Value
Unit
VI
VI
35
40
V
V
Input Voltage (for VO = 5V to 18V)
(for VO = 24V)
Thermal Resistance Junction-Cases
RθJC
5
°C/W
Thermal Resistance Junction-Air
RθJA
65
Operating Temperature Range KA78XX/A/R/RA
KA78XXI/RI
TOPR
0 ~ +125
-40 ~ +125
°C/W
°C
°C
Storage Temperature Range
TSTG
-65 ~ +150
°C
LM7805/I/R/RI ELECTRICAL CHARACTERISTICS
(Refer to test circuit, TMIN < TJ < TMAX, IO = 500mA, VI = 10V, CI= 0.33µF, CO= 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
Load Regulation
Quiescent Current
Quiescent Current Change
Output Voltage Drift
VO
∆VO
∆VO
IQ
∆IQ
∆VO/∆T
VN
5.0mA ≤ IO ≤1.0A, PO ≤ 15W
VI = 7V to 20V
VI = 8V to 20V
VO = 7V to 25V
TJ=+25°C
VI = 8V to 12V
TJ=+25°C
4.0
100
50
1.6
50
IO = 5.0mA to1.5A
9
100
9
100
IO =250mA to 750mA
4
50
4
50
5.0
8
5.0
8
TJ =+25 °C
IO = 5mA to 1.0A
VI= 7V to 25V
0.03 0.5
VI= 8V to 25V
IO= 5mA
0.3
-0.8
Short Circuit Current
ISC
Peak Current
IPK
VO
4.75 5.0 5.25
100
RO
RR
V
1.6
Output Resistance
Ripple
Rejection
Dropout Voltage
Unit
4.75 5.0 5.25
4.0
f = 10Hz to 100Khz, TA=+25 °C
f = 120Hz
VO = 8 to 18V
IO = 1A, TJ =+25 °C
f = 1KHz
Output Noise Voltage
LM7805I
LM7805
Min Typ Max Min Typ Max
4.8 5.0 5.2 4.8 5.0 5.2
0.03 0.5
0.3 1.3
73
mV
mA
mA
1.3
42
62
mV
62
-0.8
mV/ °C
42
µV/Vo
73
dB
2
2
V
15
15
VI = 35V, TA =+25 °C
230
230
mΩ
mA
TJ =+25 °C
2.2
2.2
A
* TMIN <TJ <TMAX
LM78XXI/RI: TMIN= - 40 °C, TMAX = +125 °C
LM78XX/R: TMIN= 0 °C, TMAX= +125 °C
* Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects
must be taken into account separately. Pulse testing with low duty is used.
(Refer to test circuit, TMIN <TJ <TMAX, IO=500mA, VI= 11V CI= 0.33µF, CO= 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
Ripple
Rejection
Dropout Voltage
IQ
∆IQ
∆VO/∆T
VN
RR
5.0mA ≤ IO ≤1.0A, PD ≤ 15W
VI = 8.0V to 21V
VI = 9.0V to 21V
VI = 8V to 25V
TJ=+25 °C
VI = 9V to 13V
IO =5mA to 1.5A
TJ=+25 °C
IO =250mA to750A
Min
5.75
Min
5.75
LM7806
Typ
Max
6.0
6.25
Unit
V
5.7
5.7
TJ =+25 °C
IO = 5mA to 1A
VI = 8V to 25V
6.0
6.3
5
1.5
9
3
5.0
120
60
120
60
8
6.0
6.3
5
1.5
9
3
5.0
120
60
120
60
8
0.5
VI = 9V to 25V
IO = 5mA
f = 10Hz to 100Khz, TA =+25 °C
f = 120Hz
VI = 9V to 19V
LM7806I
Typ Max
6.0
6.25
0.5
1.3
mV
mV
mA
mA
1.3
59
-0.8
-0.8
mV/ °C
45
45
µV/VO
75
dB
75
59
Output Resistance
RD
IO = 1A, TJ =+25 °C
f = 1KHz
ISC
VI= 35V, TA=+25°C
250
250
mΩ
mA
Peak Current
IPK
TJ =+25 °C
2.2
2.2
A
VD
2
2
V
19
19
* T MIN <TJ <TMAX
* Load and line regulation are specified at constant, junction temperature. Change in VO due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
(Refer to test Circuit, TMIN <TJ< TMAX, IO = 500mA, VI = 14V, CI = 0.33µF, CO= 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
Ripple
Rejection
Dropout Voltage
IQ
∆IQ
∆VO/∆T
VN
5.0mA ≤ IO ≤ 1.0A, PO ≤ 15W
VI = 10.5V to 23V
VI = 11.5V to 23V
TJ =+ 25°C VI = 10.5V to 25V
VI = 11.5V to 17V
I = 5.0mA to 1.5A
TJ = +25°C O
IO= 250mA to 750mA
LM7808I
Min Typ Max
7.7 8.0
8.3
Min
7.7
LM7808
Typ
Max
8.0
8.3
Unit
V
7.6
7.6
8.0
8.4
8.0
8.4
TJ =+25 °C
IO = 5mA to 1.0A
VI = 10.5A to 25V
5.0
2.0
10
5.0
5.0
160
80
160
80
8
5.0
2.0
10
5.0
5.0
160
80
160
80
8
mA
0.05
0.5
0.05
0.5
0.5
1.0
mA
VI = 11.5V to 25V
IO = 5mA
0.5
-0.8
1.0
f = 10Hz to 100Khz, TA =+25 °C
RR
f = 120Hz, VI= 11.5V to 21.5
VD
52
56
73
56
mV
mV
-0.8
mV/ °C
52
µV/Vo
73
dB
2
V
RO
IO = 1A, TJ=+25 °C
f = 1KHz
2
Output Resistance
17
17
ISC
VI= 35V, TA =+25 °C
230
230
mΩ
mA
Peak Current
IPK
TJ =+25 °C
2.2
2.2
A
* T MIN <TJ <TMAX
(Refer to test circuit. TMIN < TJ <TMAX, IO= 500mA, VI= 15V, CI = 0.33µF, CO = 0.1µF. unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
Ripple
Rejection
Dropout Voltage
IQ
∆IQ
∆VO/∆T
VN
RR
5.0mA ≤ IO ≤1.0A, PD ≤15W
VI= 11.5V to 24V
VI = 12.5V to 24V
VI = 11.5V to 25V
TJ=+25 °C
VI = 12V to 25v
IO = 5mA to 1.5A
TJ=+25 °C
IO = 250mA to 750mA
LM7809I
LM7809
Min Typ Max Min Typ Max
8.65
9.35 8.65
9
9.35
8.6
9
9.4
6
2
12
4
5.0
180
90
180
90
8
V
8.6
TJ=+25 °C
IO = 5mA to 1.0A
VI = 11.5V to 26V
9
9.4
6
2
12
4
5.0
180
90
180
90
8
0.5
VI = 12.5V to 26V
IO = 5mA
f = 10Hz to 100Khz, TA =+25 °C
f = 120Hz
VI = 13V to 23V
9
Unit
0.5
1.3
mV
mV
mA
mA
1.3
56
-1
-1
mV/ °C
58
58
µV/VO
71
dB
71
56
2
V
RO
IO = 1A, TJ=+25 °C
f = 1KHz
2
Output Resistance
17
17
ISC
VI= 35V, TA =+25 °C
250
250
mΩ
mA
Peak Current
IPK
TJ= +25 °C
2.2
2.2
A
VD
* T MIN <TJ <TMAX
(Refer to test circuit, TMIN <TJ <TMAX, IO= 500mA, VI =16V, CI = 0.33µF, CO= 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
IQ
Ripple
Rejection
Dropout Voltage
∆IQ
∆VO/∆T
VN
RR
5.0mA ≤ IO≤1.0A, PD ≤15W
VI = 12.5V to 25V
VI= 13.5V to 25V
VI = 12.5V to 25V
TJ =+25°C
VI = 13V to 25V
I = 5mA to 1.5A
TJ =+25°C O
IO = 250mA to 750mA
LM7810I
Min Typ Max
9.6 10
10.4
Unit
V
9.5
9.5
TJ =+25 °C
IO = 5mA to 1.0A
VI = 12.5V to 29V
10
10.5
10
3
12
4
5.1
200
100
200
400
8
10
10.5
10
3
12
4
5.1
200
100
200
400
8
mA
0.5
1.0
mA
0.5
VI = 13.5V to 29V
IO = 5mA
f = 10Hz to 100Khz, TA =+25 °C
f = 120Hz
VI = 13V to 23V
LM7810
Min Typ Max
9.6 10
10.4
mV
mV
1.0
56
-1
-1
mV/ °C
58
58
µV/Vo
71
dB
71
56
Output Resistance
RO
IO = 1A, TJ=+25 °C
f = 1KHz
17
17
ISC
VI = 35V, TA=+25 °C
250
250
mΩ
mA
Peak Current
IPK
TJ =+25 °C
2.2
2.2
A
VD
2
2
V
* T MIN <TJ <TMAX
(Refer to test circuit, TMIN<TJ<TMAX, IO = 500mA, VI=18V, CI=0.33µF, CO = 0.IµF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
IQ
Ripple
Rejection
Dropout Voltage
∆IQ
∆VO/∆T
VN
RR
5.0mA ≤ IO ≤1.0A, PD ≤15W
VI = 13.5V to 26V
VI= 14.5V to 26V
V = 13.5V to 25V
TJ =+25°C I
VI = 14V to 21V
I = 5.0mA to 1.5A
TJ =+25°C O
IO = 250mA to 750mA
LM7811I
Min Typ Max
10.6 11
11.4
Unit
V
10.5
10.5
TJ =+25 °C
IO = 5mA to 1.0A
VI = 13.5V to 29V
11
11.5
10
3.0
12
4
5.1
220
110
220
110
8
11
11.5
10
3
12
4
5.1
220
110
220
110
8
mA
0.5
1.0
mA
0.5
VI = 14.5V to 29V
IO = 5mA
f = 10Hz to 100Khz, TA =+25 °C
f = 120Hz
VI = 14V to 24V
LM7811
Min Typ Max
10.6 11
11.4
mV
mV
1.0
55
-1
-1
mV/ °C
70
70
µV/VO
71
dB
71
55
2
V
RO
IO = 1A, TJ=+25 °C
f = 1KHz
2
Output Resistance
18
18
ISC
VI = 35V, TA=+25 °C
250
250
mΩ
mA
Peak Current
IPK
TJ =+25 °C
2.2
2.2
A
VD
* T MIN <TJ <TMAX
(Refer to test circuit, TMIN <TJ <TMAX, IO=500mA, VI=19V, CI= 0.33µF, CO= 0.1.µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
IQ
Ripple
Rejection
Dropout Voltage
∆IQ
∆VO/∆T
VN
RR
5.0mA ≤ IO≤1.0A, PD≤15W
VI = 14.5V to 27V
VI= 15.5V to 27V
VI = 14.5V to 30V
TJ =+25°C
VI = 16V to 22V
I = 5mA to 1.5A
TJ =+25°C O
IO = 250mA to 750mA
LM7812I
Min Typ Max
11.5 12
12.5
f = 10Hz to 100Khz, TA =+25 °C
f = 120Hz
VI = 15V to 25V
Unit
V
11.4
11.4
TJ =+25 °C
IO = 5mA to 1.0A
VI = 14.5V to 30V
VI = 15V to 30V
IO = 5mA
LM7812
Min Typ Max
11.5 12
12.5
12
12.6
12
12.6
10
3.0
11
5.0
5.1
240
120
240
120
8
10
3.0
11
5.0
5.1
240
120
240
120
8
mA
0.1
0.5
0.1
0.5
0.5
1.0
mA
mV
mV
1.0
0.5
55
-1
-1
76
76
mV/ °C
mV/VO
71
dB
71
55
Output Resistance
RO
IO = 1A, TJ=+25 °C
f = 1KHz
18
18
ISC
VI = 35V, TA=+25 °C
230
230
mΩ
mA
Peak Current
IPK
TJ = +25 °C
2.2
2.2
A
VD
2
2
V
T MIN <TJ <TMAX
(Refer to test circuit, TMIN<TJ<TMAX, IO =500mA, VI =23V, CI =0.33µF, CO =0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
IQ
Ripple
Rejection
Dropout Voltage
∆IQ
∆VO/∆T
VN
RR
LM7815I
Min Typ Max
14.4 15
15.6
5.0mA ≤ IO≤1.0A, PD≤15W
14.2
VI = 17.5V to 30V
5
VI= 18.5V to 30V
VI = 17.5V to 30V
TJ =+25°C
VI = 20V to 26V
IO = 5mA to 1.5A
TJ =+25°C IO = 250mA to 750mA
TJ =+25 °C
IO = 5mA to 1.0A
VI = 17.5V to 30V
LM7815
Typ Max
15
15.6
Unit
V
15
11
3
12
4
5.2
15.75 14.25
300
150
300
150
8
15
15.75
11
3
12
4
5.2
300
150
300
150
8
0.5
VI = 18.5V to 30V
IO = 5mA
f = 10Hz to 100Khz, TA =+25 °C
f = 120Hz
VI = 18.5V to 28.5V
Min
14.4
0.5
1.0
mV
mV
mA
mA
1.0
54
-1
-1
mV/ °C
90
90
µV/VO
70
dB
70
54
2
V
RO
IO = 1A, TJ=+25 °C
f = 1KHz
2
Output Resistance
19
19
ISC
VI = 35V, TA=+25 °C
250
250
mΩ
mA
Peak Current
IPK
TJ =+25 °C
2.2
2.2
A
VD
* T MIN <TJ <TMAX
(Refer to test circuit, TMIN<TJ<TMAX, IO =500mA, VI =27V, CI =0.33µF, CO =0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
IQ
Ripple
Rejection
Dropout Voltage
∆IQ
∆VO/∆T
VN
RR
5.0mA ≤ IO ≤1.0A, PD ≤15W
VI = 21V to 33V
VI= 22V to 33V
VI = 21V to 33V
TJ =+25°C
VI = 24V to 30V
IO = 5mA to 1.5A
TJ =+25°C
IO = 250mA to 750mA
LM7818I
Min Typ Max
17.3 18
18.7
Unit
V
17.1
17.1
TJ =+25 °C
IO = 5mA to 1.0A
VI = 21V to 33V
18
18.9
15
5
15
5.0
5.2
360
180
360
180
8
18
18.9
15
5
15
5.0
5.2
360
180
360
180
8
mA
0.5
1
mA
0.5
VI = 22V to 33V
IO = 5mA
f = 10Hz to 100Khz, TA =+25 °C
f = 120Hz
VI = 22V to 32V
LM7818
Min Typ Max
17.3 18
18.7
mV
mV
1.0
53
-1
-1
mV/ °C
110
110
µV/VO
69
dB
69
53
2
V
RO
IO = 1A, TJ=+25 °C
f = 1KHz
2
Output Resistance
22
22
ISC
VI = 35V, TA=+25 °C
250
250
mΩ
mA
Peak Current
IPK
TJ =+25 °C
2.2
2.2
A
VD
* T MIN <TJ <TMAX
(Refer to test circuit, TMIN<TJ<TMAX, IO = 500mA, VI = 33V, CI = 0.33µF, CO = 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
VO
Line Regulation
∆VO
Load Regulation
∆VO
Quiescent Current
IQ
Ripple
Rejection
Dropout Voltage
∆IQ
∆VO/∆T
VN
RR
5.0mA ≤ IO ≤ 1.0A, PD ≤ 15W
VI = 27V to 38V
VI= 28V to 38V
VI = 27V to 38V
TJ =+25°C
VI = 30V to 36V
I = 5mA to 1.5A
TJ =+25°C O
IO = 250mA to 750mA
LM7824I
Min Typ Max
23 24
25
LM7824
Min Typ Max
23 24
25
Unit
V
22.8
22.8
24
25.25
24
25.2
17
6
15
5.0
5.2
480
240
480
240
8
17
6
15
5.0
5.2
480
240
480
240
8
mA
0.1
0.5
0.1
0.5
0.5
1
mA
VI = 28V to 38V
IO = 5mA
0.5
-1.5
1
f = 10Hz to 100KHz, TA =+25 °C
f = 120Hz
VI = 28V to 38V
160
TJ =+25 °C
IO = 5mA to 1.0A
VI = 27V to 38V
50
67
50
mV
mV
-1.5
mV/ °C
60
µV/VO
67
dB
2
V
RO
IO = 1A, TJ=+25 °C
f = 1KHz
2
Output Resistance
28
28
ISC
VI = 35V, TA=+25 °C
230
230
mΩ
mA
Peak Current
IPK
TJ =+25 °C
2.2
2.2
A
VD
* T MIN <TJ <TMAX
LM7805A/RA ELECTRICAL CHARACTERISTICS
(Refer to the test circuits. TJ = 0 to +I25 °C, IO = 1A, V I = 10V, C I= 0.33µF, C O= 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
IO = 5mA to 1A, PD ≤ 5W
VI = 7.5 to 20V
VI = 7.5 to 25V
IO = 500mA
VI = 8V to 12V
TJ =+25 °C
Load Regulation
∆VO
Quiescent Current
IQ
∆IQ
VI= 7.3V to 25V
VI= 8V to 12V
TJ =+25 °C
IO = 5mA to 1.5A
IO = 5mA to 1A
IO = 250 to 750mA
TJ =+25 °C
IO = 5mA to 1A
VI = 8 V to 25V, IO = 500mA
Min
Typ
Max
4.9
5
5.1
4.8
5
5.2
5
50
3
50
5
1.5
9
50
25
100
9
4
5.0
100
50
6
mA
0.5
0.8
mA
VI = 7.5V to 20V, TJ =+25 °C
Ripple Rejection
∆V/∆T
VN
RR
IO = 5mA
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 8V to 18V
Unit
V
V
V
0.8
-0.8
mV/ °C
10
µV/VO
68
dB
2
V
RO
IO = 1A, TJ =+25 °C
f = 1KHz
17
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
Peak Current
IPK
TJ= +25 °C
2.2
A
Dropout Voltage
VD
Output Resistance
*Load and line regulation are specified at constant, junction temperature. Change in VO due to heating effects must be taken
(Refer to the test circuits. TJ = 0 to+150 °C, IO = 1A, V I = 11V, C I= 0.33µF, C O= 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
VI = 8.6 to 21V
VI= 8.6 to 25V
IO = 500mA
VI= 9V to 13V
TJ =+25 °C
Load Regulation
∆VO
Quiescent Current
IQ
VI= 8.3V to 21V
VI= 9V to 13V
TJ =+25 °C
IO = 5mA to 1.5A
IO = 5mA to 1A
IO = 250 to 750mA
∆IQ
TJ =+25 °C
IO = 5mA to 1A
VI = 9V to 25V, IO = 500mA
∆V/∆T
VI= 8.5V to 21V, TJ =+25 °C
IO = 5mA
VN
Ripple Rejection
RR
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 9V to 19V
Min
Typ
Max
5.58
6
6.12
Unit
5.76
6
6.24
5
60
3
60
5
60
1.5
30
9
100
4
5.0
4.3
100
50
6
mA
0.5
0.8
mA
V
mV
mV
0.8
-0.8
mV/ °C
10
µ V/VO
65
dB
Dropout Voltage
VD
V
RO
IO = 1A, TJ =+25 °C
f = 1KHz
2
Output Resistance
17
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
Peak Current
IPK
TJ=+25 °C
2.2
A
(Refer to the test circuits. TJ = 0 to+150 °C, IO = 1A, V I = 14V, C I = 0.33µF, C O=0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
IO = 5mA to 1A, PD ≤15W
VI = 8.6 to 21V
VI= 10.6 to 25V
IO = 500mA
VI= 11to 17V
TJ =+25 °C
Load Regulation
∆VO
Quiescent Current
IQ
∆IQ
VI= 10.4V to 23V
VI= 11V to 17V
TJ =+25 °C
IO = 5mA to 1.5A
IO = 5mA to 1A
IO = 250 to 750mA
TJ =+25 °C
IO = 5mA to 1A
VI = 11V to 25V, IO = 500mA
Min
Typ
Max
7.84
8
8.16
7.7
8
8.3
6
80
3
80
6
2
80
40
12
100
12
5
5.0
100
50
6
mA
0.5
0.8
mA
VI= 10.6V to 23V, TJ =+25 °C
∆V/∆T
VN
Ripple Rejection
RR
IO = 5mA
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 11.5V to 21.5V
Unit
V
mV
mV
0.8
-0.8
mV /°C
10
µV/VO
62
dB
IO = 1A, TJ =+25 °C
f = 1KHz
2
V
18
ISC
VI= 35V, TA =+25°C
250
mΩ
mA
IPK
TJ=+25 °C
2.2
A
Dropout Voltage
VD
Output Resistance
RO
Peak Current
(Refer to the test circuits. TJ = 0 to +125 °C, IO = 1A, V I = 15V, C I = 0.33µF, C O = 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
VI = 11.2 to 24V
VI= 11.7 to 25V
IO = 500mA
VI= 12.5 to 19V
TJ =+25 °C
Load Regulation
∆VO
Quiescent Current
IQ
∆IQ
∆V/∆T
VN
Ripple Rejection
RR
Min
Typ
Max
8.82
9.0
9.18
8.65
9.0
9.35
6
90
4
45
VI= 11.5V to 24V
6
90
VI= 12.5V to 19V
2
45
12
100
12
5
5.0
100
50
6.0
TJ =+25 °C
IO = 5mA to 1.0A
IO = 5mA to 1.0A
IO = 250 to 750mA
TJ =+25 °C
VI = 11.7V to 25V, TJ=+25 °C
VI = 12V to 25V, IO = 500mA
0.8
IO = 5mA to 1.0A
0.5
IO = 5mA
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 12V to 22V
0.8
Unit
V
mV
mV
mA
mA
-1.0
mV/ °C
10
µV/VO
62
dB
Dropout Voltage
VD
V
RO
IO = 1A, TJ =+25 °C
f = 1KHz
2.0
Output Resistance
17
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
Peak Current
IPK
TJ=+25 °C
2.2
A
(Refer to the test circuits. TJ = 0 to+125 °C, IO = 1A, V I = 16V, C I = 0.33µF, CO = 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
VI =12.8 to 25V
VI= 12.8 to 26V
IO = 500mA
VI= 13to 20V
TJ =+25 °C
Load Regulation
Quiescent Current
∆VO
IQ
∆IQ
∆V/∆T
VN
Ripple Rejection
RR
VI= 12.5V to 25V
VI= 13V to 20V
TJ =+25 °C
IO = 5mA to 1.5A
IO = 5mA to 1.0A
IO = 250 to 750mA
TJ =+25 °C
Min
Typ
Max
9.8
10
10.2
9.6
10
10.4
8
100
4
50
8
3
100
50
12
100
12
5
5.0
100
50
6.0
VI = 13V to 26V, TJ=+25 °C
VI = 12.8V to 25V, IO = 500mA
0.5
IO = 5mA to 1.0A
0.5
0.8
IO = 5mA
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 14V to 24V
-1.0
Unit
V
mV
mV
mA
mA
mV °C
10
µV/VO
62
dB
Dropout Voltage
VD
V
RO
IO = 1A, TJ =+25 °C
f = 1KHz
2.0
Output Resistance
17
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
Peak Current
IPK
TJ=+25 °C
2.2
A
(Refer to the test circuits. TJ = 0 to +125 °C, IO = 1A, V I = 18V, C I = 0.33µF, C O = 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
VI = 13.8 to 26V
VI= 12.8 to 26V
IO = 500mA
VI= 15 to 21V
TJ =+25 °C
Load Regulation
∆VO
Quiescent Current
IQ
∆IQ
∆VO/∆T
VN
Ripple Rejection
RR
VI= 13.5V to 26V
VI= 15V to 21V
TJ =+25 °C
IO = 5mA to 1.5A
IO = 5mA to 1.0A
IO = 250 to 750mA
TJ =+25 °C
Min
Typ
Max
10.8
11.0
11.2
10.6
11.0
11.4
10
110
4
55
10
3
110
55
12
100
12
5
5.1
100
50
6.0
VI = 13.8V to 26V, TJ=+25 °C
VI = 14V to 27V, IO = 500mA
0.8
IO = 5mA to 1.0A
IO = 5mA
0.5
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 14V to 24V
0.8
Unit
V
mV
mV
mA
mA
-1.0
mV /°C
10
µV/VO
61
dB
Dropout Voltage
VD
V
RO
IO = 1A, TJ =+25 °C
f = 1KHz
2.0
Output Resistance
18
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
Peak Current
IPK
TJ=+25 °C
2.2
A
(Refer to the test circuits. TJ = 0 to +125 °C, IO = 1A, V I = 19V, C I = 0.33µF, C O= 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
VI = 14.8 to 27V
VI= 14.8 to 30V
IO = 500mA
VI= 16 to 22V
TJ =+25°C
Load Regulation
∆VO
Quiescent Current
IQ
∆IQ
∆VO/∆T
VN
Ripple Rejection
RR
VI= 14.5V to 27V
VI= 16V to 22V
TJ =+25°C
IO = 5mA to 1.5A
IO = 5mA to 1.0A
IO = 250 to 750mA
TJ =+25 °C
Min
Typ
Max
11.75
12
12.25
11.5
12
12.5
10
120
4
120
10
3
120
60
12
100
12
5
5.1
100
50
6.0
VI = 15V to 30V, TJ=+25 °C
VI = 14V to 27V, IO = 500mA
0.5
IO = 5mA to 1.0A
IO = 5mA
0.8
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 14V to 24V
0.8
Unit
V
mV
mV
mA
mA
-1.0
mV/ °C
10
µV/VO
60
dB
Dropout Voltage
VD
V
RO
IO = 1A, TJ =+25 °C
f = 1KHz
2.0
Output Resistance
18
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
Peak Current
IPK
TJ=+25 °C
2.2
A
(Refer to the test circuits. TJ = 0 to +150 °C, IO =1A, V I=23V, C I = 0.33µF, C O=0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
VI = 17.7 to 30V
VI= 17.9 to 30V
IO = 500mA
VI= 20 to 26V
TJ =+25 °C
Load Regulation
∆VO
Quiescent Current
IQ
∆IQ
∆VO/∆T
VN
Ripple Rejection
RR
VI= 17.5V to 30V
VI= 20V to 26V
TJ =+25 °C
IO = 5mA to 1.5A
IO = 5mA to 1.0A
IO = 250 to 750mA
TJ =+25 °C
Min
Typ
Max
14.7
15
15.3
14.4
15
15.6
10
150
5
150
11
3
150
75
12
100
12
5
5.2
100
50
6.0
VI = 17.5V to 30V, TJ =+25 °C
VI = 17.5V to 30V, IO = 500mA
0.5
IO = 5mA to 1.0A
IO = 5mA
0.8
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 18.5V to 28.5V
0.8
Unit
V
mV
mV
mA
mA
-1.0
mV/ °C
10
µV/VO
58
dB
Dropout Voltage
VD
V
RO
IO = 1A, TJ =+25 °C
f = 1KHz
2.0
Output Resistance
19
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
Peak Current
IPK
TJ=+25 °C
2.2
A
(Refer to the test circuits. TJ = 0 to +150 °C, IO=1A, V I = 27V, C I= 0.33µF, C O = 0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
VI = 21 to 33V
VI= 21 to 33V
IO = 500mA
VI= 21 to 33V
TJ =+25 °C
Load Regulation
∆VO
Quiescent Current
IQ
∆IQ
∆VO/∆T
VN
Ripple Rejection
RR
Dropout Voltage
VD
Output Resistance
RO
Peak Current
Min
Typ
Max
17.64
18
18.36
17.3
18
18.7
15
180
5
180
VI= 20.6V to 33V
15
180
VI= 24V to 30V
5
90
15
100
15
7
5.2
100
50
6.0
TJ =+25 °C
IO = 5mA to 1.5A
IO = 5mA to 1.0A
IO = 250 to 750mA
TJ =+25 °C
VI = 21V to 33V, TJ=+25 °C
VI = 21V to 33V, IO = 500mA
0.5
IO = 5mA to 1.0A
IO = 5mA
0.8
f = 10Hz to 100KHz
TA =+25 °C
f = 120Hz, IO = 500mA
VI = 18.5V to 28.5V
0.8
Unit
V
mV
mV
mA
mA
-1.0
mV/ °C
10
µV/VO
57
dB
IO = 1A, TJ =+25 °C
f = 1KHz
2.0
V
19
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
IPK
TJ=+25 °C
2.2
A
(Refer to the test circuits. TJ = 0 to +150 °C, IO =1A, V I = 33V, C I= 0.33µF, C O=0.1µF, unless otherwise specified)
Characteristic
Symbol
Test Conditions
TJ =+25 °C
Output Voltage
Line Regulation
VO
∆VO
VI = 27.3 to 38V
VI= 27 to 38V
IO = 500mA
VI= 21 to 33V
o
TJ =+25 C
Load Regulation
Quiescent Current
∆VO
IQ
∆IQ
∆VO/∆T
VN
Ripple Rejection
RR
VI= 26.7V to 38V
VI= 30V to 36V
TJ =+25 °C
IO = 5mA to 1.5A
IO = 5mA to 1.0A
IO = 250 to 750mA
TJ =+25 °C
Min
Typ
Max
23.5
24
24.5
23
24
25
18
240
6
240
18
6
240
120
15
100
15
7
5.2
100
50
6.0
VI = 27.3V to 38V, TJ =+25 °C
VI = 27.3V to 38V, IO = 500mA
0.5
IO = 5mA to 1.0A
IO = 5mA
0.8
f = 10Hz to 100KHz
TA = 25 °C
f = 120Hz, IO = 500mA
VI = 18.5V to 28.5V
0.8
Unit
V
mV
mV
mA
mA
-1.5
mV/ °C
10
µV/VO
54
dB
Dropout Voltage
VD
V
RO
IO = 1A, TJ =+25°C
f = 1KHz
2.0
Output Resistance
20
ISC
VI= 35V, TA =+25 °C
250
mΩ
mA
Peak Current
IPK
TJ=+25 °C
2.2
A
TYPICAL PERFORMANCE CHARACTERISTICS
Fig. 1 Quiescent Current
Fig. 3 Output Voltage
Fig. 2 Peak Output Current
Fig. 4 Quiescent Current
TYPICAL APPLICATIONS
Fig. 5 DC Parameters
Fig. 6 Load Regulation
Fig. 7 Ripple Rejection
TYPICAL APPLICATIONS (Continued)
Fig. 8 Fixed Output Regulator
Fig. 9 Constant Current Regulator
Notes:
(1) To specify an output voltage. substitute voltage value for "XX."
A common ground is required between the input and the Output
voltage. The input voltage must remain typically 2.0V above the output
voltage even during the low point on the input ripple voltage.
(2) CI is required if regulator is located an appreciable distance from
power Supply filter.
(3) CO improves stability and transient response.
Fig. 10 Circuit for Increasing Output Voltage
IRI ≥ 5 IQ
VO = VXX (1+R2/R1)+IQR2
Fig. 11 Adjustable Output Regulator (7 to 30V)
Fig. 12 High Current Voltage Regulator
Fig. 13 High Output Current with
Short Circuit Protection
Fig. 14 Tracking Voltage Regulator
Fig. 15 Split Power Supply ( ± 15V-1A)
Fig. 16 Negative Output Voltage Circuit
Fig. 17 switching Regulator
TRADEMARKS
The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is
not intended to be an exhaustive list of all such trademarks.
ACEx™
CoolFET™
CROSSVOLT™
E2CMOSTM
FACT™
FACT Quiet Series™
FAST®
FASTr™
GTO™
HiSeC™
ISOPLANAR™
MICROWIRE™
POP™
PowerTrench™
QS™
Quiet Series™
SuperSOT™-3
SuperSOT™-6
SuperSOT™-8
TinyLogic™
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER
NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD
DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT
OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT
RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
As used herein:
1. Life support devices or systems are devices or
2. A critical component is any component of a life
support device or system whose failure to perform can
systems which, (a) are intended for surgical implant into
be reasonably expected to cause the failure of the life
the body, or (b) support or sustain life, or (c) whose
support device or system, or to affect its safety or
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
effectiveness.
reasonably expected to result in significant injury to the
user.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification
Product Status
Definition
Advance Information
Formative or
In Design
This datasheet contains the design specifications for
product development. Specifications may change in
any manner without notice.
Preliminary
First Production
This datasheet contains preliminary data, and
supplementary data will be published at a later date.
Fairchild Semiconductor reserves the right to make
changes at any time without notice in order to improve
design.
No Identification Needed
Full Production
This datasheet contains final specifications. Fairchild
Semiconductor reserves the right to make changes at
any time without notice in order to improve design.
Obsolete
Not In Production
This datasheet contains specifications on a product
that has been discontinued by Fairchild semiconductor.
The datasheet is printed for reference information only.
ANEXO B – Esquemático
ANEXO B.1 – Drivers
2
1
B
L3
L2
L1
GND
+5V
V
B
3
Dir_x
Freq_x
L4
4
BORN-3 BORN-3 BORN-3
U11
1
2
3
U10
1
2
3
1
2
3
U9
U14 7805
VIN
+5V
GND
U15
VIN
D1
Q5
7805
+5V
GND
D04AZ3_3
150
bd243
Q6
bd243
R4
Q7
150
U4 saa1042
1 L2
L3 16
2 VD
VM15
3
14
L1
L4
R5
150
R6
R1
1k
R7
150
6
11
VCC 10
7 SET
8 CLK CW/CCW 9
F/H
GND
bd243
Q8
bd243
A
A
Setubal
Page Size:
B
Luis Rita
Pedro Silva
Revision:
4
3
2
-
6 de Outubro de 2003
1
Pagina
1 de
1
ANEXO B.2 – Principal
4
3
2
1
FONTE
7805
U21
VIN
+5V
GND
C3
1u
B
B
C6 47u
U17 MX7828
AIN6
AIN7
AIN5
AIN8
AIN4
VDD
AIN3
A0
AIN2
A1
AIN1
A2
TP
DB7
DB0
DB6
BD1
DB5
DB2
DB4
DB3
/CS
/RD
RDY
/INT
VREF+
GND VREF-
89C51
P1.0
VCC
P1.1
P0.0
P1.2
P0.1
P1.3
P0.2
P1.4
P0.3
P1.5
P0.4
P1.6
P0.5
P1.7
P0.6
RST
P0.7
RXD-P3.0
/EA-VPP
TXD-P3.1 ALE-/PROG
P3.2
PSEN
P3.3
P2.7
P3.4
P2.6
P3.5
P2.5
P3.6
P2.4
P3.7
P2.3
XTAL2
P2.2
XTAL1
P2.1
GND
P2.0
C7 100n
MAX233
U2
T2IN R2OUT
T1IN
R2IN
R1OUT T2OUT
R1IN
VT1OUT
C2GND
C2+
VCC
V+
C1C1+
GND
VCSC2+
U13
C2
botao
U38
2
470
U34
D16
U27
ldr
R6
R7
R8
10k
10k
10k
C5
33p
SERIE1 SERIE2
D18
led
2
2
ldr
11M
C4
33p
1
10k
U28
1
R5
ldr
2
2
10k
ldr
U29
1
10k
R4
U30
1
R3
ldr
2
10k
ldr
2
R2
U31
1
10k
2
A
ldr
U32
1
2
R1
1
1
ldr
U33
4
Dir_2
Freq_2
Dir_1
Freq_1
R9
D17
220 R10
led
led
220 R11
D19
A
led
220 R12
220 R13
Setubal
Page Size:
B
Luis Rita
Pedro Silva
Revision:
4
3
2
-
6 de Outubro de 2003
1
Pagina
1 de
1
ANEXO C – PCB
ANEXO C.1 – Drivers
ANEXO C.2 – Principal
ANEXO C.3 – Pistas para os
contactos deslizantes
ANEXO D – Programa do
Microcontrolador
ANEXO D.1 – Sem Ligação
ao PC
$mod51
org 0000h
ljmp inicio
;*******************************************************************************
*********************************************
configuracoes:
mov pcon, #80h
;configuracao porta serie
mov tmod, #021h
mov scon, #050h
;modo 0
mov ie, #00h
setb
tr1
;Inicia o TIMER 1
mov
th1, #00FDH
;Valor Baud Rate=19200 bps
mov p1,#0ffh
mov p2,#0ffh
mov p0,#0ffh
mov 40h,#00h
mov 41h,#5Ah
mov 42h,#00h
mov 43h,#5Ah
mov 47h,#00h
mov 50h,#00h
mov 49h,#00h
mov 44h,#00h
;referencia
ret
;*******************************************************************************
*********************************************
referencia:
; procedimento que faz com que após se dar o
reset a cabeça dê uma volta completa
; no eixo da azimute em busca do maior valor de
luz. esse valor vai ser considerado como
mov r5, #14H
MOV R6, #0FFH
; a referência e a cabeça só irá responder para
valores de luz acima desse valor. essa volta
MOV R7, #8CH
; de 360 graus é feita com a cabeça na posição
de 45graus, pois é nesta posição que a
c1:
: cabeça tem um raio de acção maior
acall cima
acall conversao
acall maior
mov a,44h
clr c
subb a, 39h
jnc ref1
mov 44h, 39h
ref1:
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r5,c1
C2:
acall esquerda1
acall conversao
acall maior
mov a,44h
clr c
subb a, 39h
jnc ref2
mov 44h, 39h
ref2:
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r6, c2
C3:
acall esquerda1
acall conversao
acall maior
mov a,44h
clr c
subb a, 39h
jnc ref3
mov 44h, 39h
ref3:
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r7, c3
ret
;*******************************************************************************
*********************************************
inicial:
; procedimento que coloca a cabeça na posição
0graus após esta ter feito a busca da
mov r5, #14h
; referência
c6:
acall baixo
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r5,c6
ret
;*******************************************************************************
*********************************************
delay:
; atraso para ser usado sempre que necessário,
neste caso nos sinais de controle do
mov r1,#0FFh
ciclo1:
; motor, nos sinais de conversão do ADC, etc...
mov r2,#0Ah
ciclo2:
djnz r2,ciclo2
djnz r1,ciclo1
ret
;*******************************************************************************
*********************************************
envia_porta:
; procedimento que permite enviar o que quer que
seja para o exterior, através da
mov sbuf, a
; porta série, utilizando o protocolo RS-232
envia_porta2:
jnb ti,envia_porta2
clr ti
ret
;*******************************************************************************
*********************************************
recebe_porta:
; procedimento que permite receber o que quer
que seja para do exterior, através da
mov a, sbuf
; porta série, utilizando o protocolo RS-232
recebe_porta2:
jnb ri,recebe_porta2
clr ri
ret
;*******************************************************************************
*********************************************
canal0:
o canal do ADC que se pretende
; procedimentos que servem para seleccionar qual
clr p2.4
clr p2.5
clr p2.6
ret
canal1:
setb p2.4
clr p2.5
clr p2.6
ret
canal2:
clr p2.4
setb p2.5
clr p2.6
ret
canal3:
setb p2.4
setb p2.5
clr p2.6
ret
canal4:
; utilizar
clr p2.4
clr p2.5
setb p2.6
ret
canal5:
setb p2.4
clr p2.5
setb p2.6
ret
canal6:
clr p2.4
setb p2.5
setb p2.6
ret
canal7:
setb p2.4
setb p2.5
setb p2.6
ret
;*******************************************************************************
*********************************************
converter:
; procedimento que permite fazer a conversão dos
sinais analógicos que vêm das LDR´s
clr p2.0
nop
clr p2.1
; em valores digitais
nop
clr p2.3
nop
mov a,p0
setb p2.1
setb p2.3
setb p2.2
setb p2.0
ret
;*******************************************************************************
*********************************************
cima:
; procedimento que faz com que a cabeça se
movimente para cima no eixo da elevação
clr p1.1
clr p1.0
nop
nop
setb p1.0
nop
nop
clr p1.0
acall incremento
ret
;*******************************************************************************
*********************************************
baixo:
; procedimento que faz com que a cabeça se
movimente para baixo no eixo da elevação
setb p1.1
clr p1.0
nop
nop
setb p1.0
nop
nop
clr p1.0
acall decremento
ret
;*******************************************************************************
*********************************************
direita:
; procedimento que faz com que a cabeça se mova
para a direita no eixo da azimute
mov a,41h
sensor que no lado positivo
; se a cabeça se encontrar no lado negativo, o
CLR C
subb a, 43h
a esquerda
jc esquerda1
CJNE A,#00H,VAI
mov a, 40h
CLR C
subb a, 42h
jc esquerda1
VAI:
jmp direita1
; era para se mover para a direita agora é para
RET
;*******************************************************************************
*********************************************
DIREITA1:
clr p1.3
clr p1.2
nop
nop
nop
setb p1.2
nop
nop
nop
clr p1.2
ret
;*******************************************************************************
*********************************************
esquerda:
; procedimento que faz com que a cabeça se mova
para a esquerda no eixo da azimute
mov a,41h
sensor que no lado positivo
; se a cabeça se encontrar no lado negativo, o
CLR C
subb a, 43h
a direita
jc direita1
CJNE A,#00H,VEM
mov a, 40h
; era para se mover para a esquerda agora é para
CLR C
subb a, 42h
jc direita1
VEM:
jmp esquerda1
RET
;*******************************************************************************
*********************************************
ESQUERDA1:
setb p1.3
clr p1.2
nop
nop
nop
setb p1.2
nop
nop
nop
clr p1.2
ret
;*******************************************************************************
*********************************************
conversao:
; procedimento que converte os valores
analógicos das LDR´s para digitais,
posções de memória do micro
acall canal0
acall converter
mov 30H,a
; até um máximo de 8 canais e os guarda em
acall canal1
acall converter
mov 31H,a
acall canal2
acall converter
mov 32H,a
acall canal3
acall converter
mov 33H,a
acall canal4
acall converter
mov 34H,a
acall canal5
acall converter
mov 35H,a
acall canal6
acall converter
mov 36H,a
acall canal7
acall converter
mov 37H,a
ret
;*******************************************************************************
*********************************************
maior:
está a captar mais luz e
; procedimento que determina qual o sensor que
mov a,30h
mov r1,31h
clr c
subb a,r1
jc um
mov 38h,#0d
mov a,30h
mov 39h,a
jmp dois
um:
mov 38h,#1d
mov 39h,r1
dois:
mov a,32h
mov r1,39h
clr c
subb a,r1
jc tres
mov 38h,#2d
mov a,32h
mov 39h,a
tres:
mov a,33h
mov r1,39h
clr c
subb a,r1
jc quatro
mov 38h,#3d
mov a,33h
; guarda esse valor numa posição de memória
mov 39h,a
quatro:
mov a,34h
mov r1,39h
clr c
subb a,r1
jc cinco
mov 38h,#4d
mov a,34h
mov 39h,a
cinco:
mov a,35h
mov r1,39h
clr c
subb a,r1
jc seis
mov 38h,#5d
mov a,35h
mov 39h,a
seis:
mov a,36h
mov r1,39h
clr c
subb a,r1
jc sete
mov 38h,#6d
mov a,36h
mov 39h,a
sete:
nop
ret
;*******************************************************************************
*********************************************
incremento:
memória sempre que a cabeça
; procedimento que incrementa uma posição de
MOV a, 41h
cjne a,#0ffh,zero
; se mova para cima, para depois se conseguir
saber se esta se encontra no lado positivo
mov 41h,#00h
90)
inc 40h
; (maior que 90) ou no lado negativo (menor que
jmp fim
zero:
inc 41h
fim:
nop
ret
;*******************************************************************************
*********************************************
decremento:
memória sempre que a cabeça
; procedimento que decrementa uma posição de
mov a,41h
cjne a,#00h,igu
; se move para baixo, para depois se conseguir
saber se esta se encontra no lado positivo
mov 41h,#0ffh
90)
DEC 40h
jmp fim2
; (maior que 90) ou no lado negativo (menor que
igu:
DEC 41h
fim2:
nop
ret
;*******************************************************************************
*********************************************
procura:
; procedimento que faz com que a cabeça após
9,55s sem captar nenhum valor de luz
mov 48h, 44h
MOV R6, #0FFH
; acima da referência, executa uma volta de
360graus em procura de um valor de luz
MOV R7, #8CH
; superior á referência
C8:
inc 50h
acall esquerda1
acall conversao
acall maior
mov a,48h
clr c
subb a, 39h
jnc ref6
mov 48h,39h
mov 49h,50h
ref6:
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r6, c8
C9:
inc 50h
acall esquerda1
acall conversao
acall maior
mov a,48h
clr c
subb a, 39h
jnc ref5
mov 48h, 39h
mov 49h, 50h
ref5:
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r7, c9
ret
;*******************************************************************************
*********************************************
certa:
45 graus ou de -45graus
; procedimento que coloca a cabeça na posição de
mov a, #59h
; dependendo do lado onde esta se encontra,
antes de esta executar o procedimento
clr c
subb a, 41h
jnc certa3
certa1:
mov a, #77h
clr c
subb a, 41h
jnc certa5
mov a, 41h
mov 51h, #77h
clr c
subb a, 51h
mov r5, a
certa2:
acall baixo
acall delay
; de procura de luz
acall delay
acall delay
acall delay
acall delay
djnz r5,certa2
mov 41h, #78h
ljmp certa9
certa5:
mov r7, a
certa6:
acall cima
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r7,certa6
mov 41h, #78h
ljmp certa9
certa3:
mov a, #45h
clr c
subb a, 41h
jnc certa7
mov a, 41h
mov 51h, #45h
clr c
subb a, 51h
mov r6, a
certa4:
acall baixo
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r6,certa4
mov 41h, #46h
ljmp certa9
certa7:
mov r7, a
certa8:
acall cima
acall delay
acall delay
acall delay
acall delay
acall delay
djnz r7,certa8
mov 41h, #46h
certa9:
nop
ret
;*******************************************************************************
*********************************************
inicio:
; Programa Principal:
acall configuracoes
; é feita a conversão dos valores das
LDR´s e depois de acordo com esses valores
acall referencia
acall inicial
á cabeça para onde esta se deve mover.
; o microcontrolador vai dar a indicação
; ou seja, se a diferença de valores
entre os dois pares de sensores fôr menor que 5
inicio1:
; a cabeça está centrada, se fôr
superior a 5 o micro vai dar indicação para a cabeça
mov 47h, #00h
mov 50h,#00h
; se mover na direcção ou nas direcções
do sensor do par de sensores que tiver a
inicio4:
; captar maior valor de luz.
acall conversao
acall maior
nao captar um valor de luz superior á
nop
; por outro lado, sempre que a cabeça
sendo incrementada, para que depois o
; referência uma posição de memória vai
mov a, 39h
clr c
executar o movimento de procura de luz
subb a, 44h
jc inicio5
quat:
mov a, 30h
clr c
subb a, 34h
jc quat1
mov 52h, #5d
clr c
subb a, 52h
jc lado
jnc ci
quat1:
mov a, 34h
clr c
subb a, 30h
mov 52h, #5d
subb a, 52h
jc lado
jnc ba
lado:
mov a, 33h
clr c
subb a, 31h
; micro dê indicação á cabeça para esta
jc quat3
mov 52h, #5d
clr c
subb a, 52h
jc inicio1
jnc dir
quat3:
mov a, 31h
clr c
subb a, 33h
mov 52h, #5d
clr c
jc inicio1
jnc esq
ci:
mov a, 39h
clr c
subb a, 44h
jc inicio2
mov a,#174d
clr c
subb a, 41h
jc inicio1
acall cima
acall delay
acall delay
acall delay
acall delay
acall delay
ljmp lado
inicio5:
ljmp inicio2
ba:
mov a, 39h
clr c
subb a, 44h
jc inicio2
mov a,#5d
clr c
subb a, 41h
jnc inicio6
acall baixo
acall delay
acall delay
acall delay
acall delay
acall delay
ljmp lado
inicio6:
ljmp inicio1
dir:
mov a, 39h
clr c
subb a, 44h
jc inicio2
acall direita
acall delay
acall delay
acall delay
acall delay
acall delay
ljmp inicio1
esq:
mov a, 39h
clr c
subb a, 44h
jc inicio2
acall esquerda
acall delay
acall delay
acall delay
acall delay
acall delay
ljmp inicio1
inicio2:
inc 47h
acall delay
acall delay
acall delay
acall delay
acall delay
acall delay
mov a, #250d
clr c
subb a, 47h
jc inicio3
ljmp inicio4
inicio3:
acall delay
acall delay
acall delay
acall delay
acall delay
mov 49h,#00h
acall certa
acall procura
mov a, #01h
clr c
subb a, 49h
jc inicio9
ljmp inicio1
inicio9:
mov r6, 49h
C10:
acall esquerda1
acall delay
acall delay
acall delay
acall delay
djnz r6, c10
ljmp inicio1
end
ANEXO D.2 – Com ligação
ao PC
$mod51
org 0000h
ljmp inicio
;*****************************************************************************
configuracoes:
mov pcon, #80h
mov tmod, #021h
mov scon, #050h
mov ie, #00h
setb
tr1
mov
th1, #00FDH
;configuracao porta serie SMOD-1 para 19200 bps
;modo 0
;Inicia o TIMER 1
;Valor Baud Rate=19200 bps
mov p1,#0ffh
ret
delay:
um:
mov p2,#0ffh
mov p0,#0ffh
mov r1,39h
mov r2,#0Ah
;////////////////////////////////////////////////////////////////
dois:
djnz r2,dois
djnz r1,um
ret
envia_porta:
mov sbuf, a
;enviar para a porta serie
envia_porta2:
jnb ti,envia_porta2
clr ti
ret
recebe_porta:
mov a, sbuf
recebe_porta2:
ret
jnb ri,recebe_porta2
clr ri
;canais do ADC
;receber da porta serie
canal0:
ret
canal1:
ret
canal3:
ret
canal4:
ret
clr p2.4
clr p2.5
clr p2.6
setb p2.4
clr p2.5
clr p2.6
setb p2.4
setb p2.5
clr p2.6
clr p2.4
clr p2.5
setb p2.6
;realização da conversão
converter:
clr p2.0
nop
clr p2.1
nop
clr p2.3
nop
mov a,p0
setb
setb
setb
setb
p2.1
p2.3
p2.2
p2.0
ret
;movimentos
cima:
clr p1.1
clr p1.0
acall delay
setb p1.0
acall delay
clr p1.0
ret
baixo:
setb p1.1
clr p1.0
acall delay
setb p1.0
acall delay
clr p1.0
ret
direita:
ret
clr p1.3
clr p1.2
acall delay
setb p1.2
acall delay
clr p1.2
esquerda:
setb p1.3
clr p1.2
acall delay
setb p1.2
acall delay
clr p1.2
ret
;conversão dos quatro canais utilizados
conversao:
acall canal0
acall converter
mov 30H,a
acall canal1
acall converter
mov 31H,a
acall canal3
acall converter
mov 33H,a
acall canal4
acall converter
mov 34H,a
ret
; enviar para o PC os valores
envdados:
mov a,30h
acall envia_porta
mov a,31h
acall envia_porta
mov a,33h
acall envia_porta
mov a,34h
acall envia_porta
ret
;*****************************************************************************
inicio:
acall configuracoes
acall recebe_porta
inicio1:
acall conversao
acall envdados
acall recebe_porta
CJNE a,#'1',ci
ljmp inicio1
;movimento em elevaçao
ci:
cjne a,#'2',ba
acall delay
acall cima
ljmp segundo
ba:
cjne a,#'3',dir
acall delay
acall baixo
ljmp segundo
;movimento em azimute
segundo:
acall recebe_porta
CJNE a,#'1',ci
ljmp inicio1
dir:
cjne a,#'4',esq
acall delay
acall direita
ljmp inicio1
esq:
cjne a,#'5',inicio1
acall delay
acall esquerda
ljmp inicio1
end
ANEXO E – Programa em
Visual Basic
Form1 - 1
Dim
Dim
Dim
Dim
Dim
Dim
Dim
Dim
Dim
Dim
Dim
Dim
recebeu As Boolean
max As Variant
indice As Variant
buffer() As Byte
inicio As Boolean
resposta As Byte
espera As Boolean
fimciclo As Boolean
reaccao As Integer
ficheiro As Variant
referencia As Integer
velocidade As Integer
Private Sub Command1_Click()
Dim
Dim
Dim
Dim
Dim
um As Integer
dois As Integer
tres As Integer
quatro As Integer
canaux As Integer
Dim enviar As Variant
Dim posicaoY As Integer
posicaoY = 80
' abrir ou criar caso não exista i ficheiro dados.txt
Open "C:\DADOS.txt" For Output Shared As #1
fimciclo = False
' informação para o micro começar a enviar os dados
MSComm1.Output = "i"
Do
' teste para sair do programa
If fimciclo Then
Exit Do
End If
' fazer uma espera para que os motores possam responder atempadamente
Timer1.Interval = velocidade
Timer1.Enabled = True
espera = False
Do
If espera = True Then
Exit Do
End If
DoEvents
Loop
Form1 - 2
inicio = True
Do
If recebeu = True Then
recebeu = False
' Mostrar valores recebidos
Text1.Text
Text2.Text
Text3.Text
Text4.Text
=
=
=
=
buffer(0)
buffer(2)
buffer(4)
buffer(6)
um = buffer(0)
dois = buffer(2)
tres = buffer(4)
quatro = buffer(6)
' Calculo da diferenca dos pares de valores
Text7.Text = um - quatro
Text8.Text = dois - tres
' guardar para ficheiro o valor das subtracções
Write #1, um - quatro; dois - tres
If um < referencia Then
um = referencia
End If
If dois < referencia Then
dois = referencia
End If
If tres < referencia Then
tres = referencia
End If
If quatro < referencia Then
quatro = referencia
End If
' calculo do caracter a enviar para o micro fazer actuar os motores
If Abs(um - quatro) > reaccao Then
If um < quatro Then
posicaoY = posicaoY + 1
enviar = "3"
GoTo segundo
Else
Form1 - 3
posicaoY = posicaoY - 1
enviar = "2"
GoTo segundo
End If
End If
enviar = "1"
End If
segundo:
Text9.Text = posicaoY
' Testar se estamos nos limites da elevação
If posicaoY < 1 Then
enviar = "1"
posicaoY = posicaoY + 1
End If
If posicaoY > 159 Then
enviar = "1"
posicaoY = posicaoY - 1
End If
If posicaoY < 80 Then
canaux = dois
dois = tres
tres = canaux
End If
If Abs(dois - tres) > reaccao Then
If dois < tres Then
If enviar = "1" Then
MSComm1.Output = "5"
Exit Do
End If
Exit Do
End If
Exit Do
End If
Else
Exit Do
End If
Form1 - 4
Exit Do
End If
Exit Do
End If
End If
End If
If enviar <> "1" Then
Form2.Timer1.Interval = 1
Form2.Timer1.Enabled = True
End If
MSComm1.Output = enviar
Exit Do
DoEvents
Loop
DoEvents
Loop
Close #1
End Sub
' parar a execução do programa
fimciclo = True
End Sub
' Sair do programa
End
End Sub
' mudar do form 1 para o form 2
Form2.Show
Form1.Hide
Form1 - 5
End Sub
Private Sub Form_Load()
' Abrir a porta serie e inicializar variaveis
MSComm1.PortOpen = True
inicio = False
Text5.Text = reaccao
Text6.Text = referencia
VScroll1.Value = 5
VScroll2.Value = 200
VScroll3.Value = 50
End Sub
Private Sub MSComm1_OnComm()
Dim sMessage As String
' guardar o que vem da porta serie para a variavel buffer()
Select Case MSComm1.CommEvent
Case comEvReceive
buffer() = MSComm1.Input
recebeu = True
End Select
'SetStatus (sMessage), False
End Sub
Private Sub Timer1_Timer()
' esperar pelo timer
espera = True
End Sub
Private Sub VScroll1_Change()
' Actualizar o valor da sensibilidade
reaccao = VScroll1.Value
Text5.Text = reaccao
End Sub
' Actualizar o valor de referencia
referencia = VScroll2.Value
Text6.Text = referencia
End Sub
' Actualizar a frequencia de trabalho
Form1 - 6
velocidade = VScroll3.Value
Text10.Text = velocidade
End Sub
Private Sub Form_Resize()
' Para não se alterar o tamanho da janela do programa
Form2.Height = 9200
Form2.Width = 11500
End Sub
Form2 - 1
Dim
Dim
Dim
Dim
y_seguinte1, y_seguinte2 As Long
y_actual1, y_actual2 As Long
num As Integer
escala As Integer
Private Sub escalatensao()
escala = Combo2.Text
lblV1.Caption = 1 * escala
lblV_1.Caption = -1 * escala
End Sub
Private Sub Combo1_Click()
num = 0
y_actual1 = 4826
y_actual2 = 4826
Cls
End Sub
Private Sub Combo2_Click()
num = 0
y_actual1 = 4826
y_actual2 = 4826
Cls
escalatensao
End Sub
Private Sub Form_Load()
' Inicialização das variaveis
Form2 - 2
num = 0
y_actual1 = 4826
y_actual2 = 4826
Combo1.AddItem "1"
Combo1.AddItem "2"
Combo1.AddItem "5"
Combo1.AddItem "10"
Combo1.AddItem "15"
Combo1.AddItem "20"
Combo1.AddItem "30"
Combo1.AddItem "40"
Combo1.Text = 10
Combo2.AddItem "1"
Combo2.AddItem "2"
Combo2.AddItem "5"
Combo2.AddItem "10"
Combo2.Text = 5
escalatensao
End Sub
Private Sub
Dim vert As
Dim hori As
Dim color1,
poevalor()
Integer
Integer
color2, grossura1, grossura2 As Integer
'ler valores do form1 para mostrar no grafico
vert = Form1.Text7.Text
hori = Form1.Text8.Text
'definir grossura da linha
grossura1 = 2
grossura2 = 2
If vert < -10 * escala - 5 Then
vert = -10 * escala - 5
grossura1 = 1
End If
If vert > 10 * escala + 5 Then
vert = 10 * escala + 5
grossura1 = 1
End If
If hori < -10 * escala - 5 Then
hori = -10 * escala - 5
grossura2 = 1
End If
If hori > 10 * escala + 5 Then
hori = 10 * escala + 5
grossura2 = 1
End If
Form2 - 3
y_seguinte1 = 4826 - vert * 268 / escala
y_seguinte2 = 4826 - hori * 268 / escala
If num >= 40 * Combo1.Text Then
num = 0
Cls
End If
If Abs((4826 - y_actual1) / (268 / escala)) < Form1.Text5 And Abs(vert) < Fo
rm1.Text5 Then
color1 = 12
Else
color1 = 4
End If
If Abs((4826 - y_actual2) / (268 / escala)) < Form1.Text5 And Abs(hori) < Fo
rm1.Text5 Then
color2 = 9
Else
color2 = 1
End If
DrawWidth = grossura1
Line (1200 + 240 / Combo1.Text * num, y_actual1)-(1200 + 240 / Combo1.Text *
(num + 1), y_seguinte1), QBColor(color1)
y_actual1 = y_seguinte1
DrawWidth = grossura2
Line (1200 + 240 / Combo1.Text * num, y_actual2)-(1200 + 240 / Combo1.Text *
(num + 1), y_seguinte2), QBColor(color2)
y_actual2 = y_seguinte2
num = num + 1
End Sub
' sai do form2 para o from1
Form1.Show
Form2.Hide
End Sub
Private Sub Form_Resize()
' Serve para não se alterar o tamanho da janela do programa
Form2.Height = 9200
Form2.Width = 11500
Form2 - 4
End Sub
Private Sub Timer1_Timer()
'actualiza o grafico
poevalor
End Sub
ANEXO F – Lista de
material
LISTA DE MATERIAL
Quantidade
2
1
1
2
8
5
8
1
8
1
1
1
1
2
1
2
8
5
1
1
2
1
2
4
1
Referência /Descrição
Valor
AT89C51
MX7828
MAX233A
SAA1042
BD248
7805
Resistência
10KOhm
Resistência
1KOhm
Resistência
150 Ohm
Resistência
470 Ohm
Condensador
47µF
Condensador
1µF
Condensador
100nF
Condensador
33pF
Cristal
11MHz
Zener
3,9 V
Born ligação de 3 entradas
Dissipador
Botão de pressão
Suporte físico
Contactos deslizantes
Cabo com ligação à porta série
Motor passo-a-passo unipolar
LDRs
Bola de plástico
ANEXO G – Desenho em
Mechanical

MAX220–MAX249 - Instituto Politécnico de Setúbal

Transcription

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