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Switching Regulator
Voltage Regul ators Regulators Voltage Voltage Regulator Regulator Applications Applications Io Voltage Regulator Ui Ro Uo DC Regulated Load DC Unregulated Uo Ui t t Voltage Voltage Regulator Regulator Applications Applications Output Compensation Current Limit Current Limit DC DC Voltage Voltage Regulators Regulators Voltage Regulators Classification Voltage Regulators Pulse Regulators Continuous Regulators Parametric Regulators Compensatory Regulators DC DC Voltage Voltage Regulators Regulators Application Basic Parameters: -Output Voltage- Vout -Input Voltage Range- Vin -Stabilization Ratio- IR -Max. Output Current- Iout max -Short-Circuit Output Current- Isc -Efficiency, -Temperature Range. ∆Uwy Uwy IR = • 100% ∆Uwe Uwe DC s DC Voltage Voltage Regulator Regulators Uo Working Area Uo Io Iomin Iomax Output Characteristic DC DC Voltage Voltage Regulators Regulators Uo Uo Working Area Ui U imin Transfer Characteristic Uimax Zener Zener Diode Diode-- Parametric Parametric Regulator Regulator The parametric regulator uses as operating principle the nonlinear currentvoltage characteristic of the Zener diode. Io Rs Iz Ui Dz Uz Ro Uo DC Unregulated Load Uo ↑, Io ↑, Iz ↓, Uz ↓, Uo ↓ Vimax − Vz Rsmin = Izmax + Iomin Vimin − Vz Rsmax = Izmin + Iomax Zener Zener Diode Diode-- Parametric Parametric Regulator Regulator IF UR Uz N Uz max Uz min UF Izmin Iz N Iz max Zener Diode Characteristic Zener Zener Diode Diode-- Parametric Parametric Regulator Regulator Uz Uz U 'Z = U Z + U BE T U BE High Power Zener Diode U BE Parametric Parametric Regulators Regulators Rs T Ui Uz U O = U Z − U BE Ro Uo Parametric Regulator Voltage With Folower Output Parametric Parametric Regulators Regulators Ii Iz Io Uz Ui T Ro Uo Ii = Iz + Io Paraller Parametric Regulator Parametric Parametric Regulators Regulators Ii T Io Rs Ui Uz Ro Uo Ii ≈ Io Iz Serial Parametric Regulator Uo ↓, Io ↓, Ib ↓, Iz ↑, Uz ↑, Uo ↑ Compensatory Compensatory Regulator Regulator T R1 Ui k + Uo R2 R2 ) = Uref R1 + R2 R1 Uo = Uref(1 + ) R2 Uo( Uref Simply Compensatory Regulator Compensatory Compensatory Regulators Regulators T Rs Ui R1 Uo k + R2 Uz Uo = Uz • (1 + Simply Compensatory Regulator ver.1. R1 ) R2 Compensatory Compensatory Regulators Regulators T Uz Ui R1 Uo + k - R2 Rs R2 Uo = Uref • (1 + ) R1 Simply Compensatory Regulator ver.2. Protections Protections in in Voltage Voltage Regulators Regulators Negative Voltage Protection Reverse Voltage Protection Current Limit Overvoltage protection T Ui k Thermal Protection Uo k Uref, Error Amplifier PPrecision recision IIntegrated-Circuit ntegrated-Circuit V oltage R egulator UA723 Voltage Regulator UA723 V+ Frequency Compensation FC Invert Input Vc IN- Temperature Compensated Zener + Vo Current Source Voltage Reference Amplifier V- Error Amplifier IN+ Vref Non Invert Input Cl Cs Current Limit Schematic Diagram Vz PPrecision recision IIntegrated-Circuit ntegrated-Circuit V oltage R egulator UA723 Voltage Regulator UA723 Application Basic Parameters Parameter Range U input 9,5V-40V U output 2V-37V I output max 150 mA U reference 6,8V-7,5V I standby Max 4mA PPrecision recision IIntegrated-Circuit ntegrated-Circuit V oltage R egulator UA723 Voltage Regulator UA723 Output Compensation Current Limit Current Limit Schematic Diagram [Source: www.elportal.pl] PPrecision recision IIntegrated-Circuit ntegrated-Circuit V oltage R egulator UA723 Voltage Regulator UA723 V+ RA - Tc + Td Error Amplifier Te Rsc Ube=0,6V Iout Ro Current Limit PPrecision recision IIntegrated-Circuit ntegrated-Circuit V oltage R egulator UA723 Voltage Regulator UA723 R3 = V+ Vin Rsc Vref Cl 723 R1 Vc Vo R1 • R2 R1 + R2 Cs IN- IN+ Cref R3 V- Fc 100pF R2 Basic Low-Voltage Regulator (VO = 2 V to 7 V) Vout PPrecision recision IIntegrated-Circuit ntegrated-Circuit V oltage R egulator UA723 Voltage Regulator UA723 R3 = V+ Vin Rsc Vref Cl 723 R3 Vc Vo Cs IN- IN+ R1 • R2 R1 + R2 V- R1 Fc Vout 100pF R2 Basic High-Voltage Regulator (VO = 7 V to 37 V) PPrecision recision IIntegrated-Circuit ntegrated-Circuit V oltage R egulator UA723 Voltage Regulator UA723 Vin V+ Vref Vc Vo T Rsc Cl 723 Cs IN- IN+ V- R1 Fc Vout 500pF R2 High Power Positive-Voltage Regulator (External npn Pass Transistor) 33-Terminal -Terminal 11 A A Positive Positive Voltage Voltage Regulator Regulator 78xx 78xx 1 2 3 1 INPUT 2 GND 3 OUTPUT Type Uout [V] Uin max [V] Iout max [A] 7805 5 35 1 7806 6 35 1 7808 8 35 1 7809 9 35 1 7810 10 35 1 7812 12 35 1 7815 15 35 1 7818 18 35 1 7824 24 40 1 Application Basic Parameters 33-Terminal -Terminal 11 A A Positive Positive Voltage Voltage Regulator Regulator 78xx 78xx 1 IN Series Pass Element Current Generator Starting Circuit Reference Voltage 3 OUT SOA Protection Error Amplifier Thermal Protection 78xx Block Diagram 2 GND 33-Terminal -Terminal 11 A A Positive Positive Voltage Voltage Regulator Regulator 78xx 78xx 1 IN 78xx 3 OUT 2 GND V in 330 nF 78xx- Typical Application V out 100 nF 33-Terminal -Terminal 11 A A Positive Positive Voltage Voltage Regulator Regulator 78xx 78xx 1 IN 78xx 2 GND V in 3 OUT R1 100 nF V out 330 nF R2 Circuit for Increasing Output Voltage 33-Terminal -Terminal 11 A A Positive Positive Voltage Voltage Regulator Regulator 78xx 78xx T1 3Ω 1 IN 78xx 3 OUT 2 GND V in 330 nF V out 100 nF High-Current Voltage Regulator 33-Terminal -Terminal 11 A A Positive Positive Voltage Voltage Regulator Regulator 78xx 78xx Rsc 3Ω T2 T1 1 IN 78xx 3 OUT V in 2 GND 330 nF V out 100 nF High Output Current with Short-Circuit Protection 33-Terminal -Terminal 11 A A Positive Positive Voltage Voltage Regulator Regulator 78xx 78xx TO92 Iomax=500mA TO2 TO220 Iomax=1A-3A LM78xx Pacakges Iomax=1A-3A 33-Terminal -Terminal 11 A A Positive Positive Voltage Voltage Regulator Regulator 78xx 78xx Heatsinks [Source: http://tme.com/] 33-Terminal -Terminal 11 A ive Voltage A Negat Negative Voltage Regulator Regulator 79xx 79xx 1 2 3 1 GND 2 INPUT 3 OUTPUT Type Uout [V] Uin max [V] Iout max [A] 7905 -5 -35 1 7906 -6 -35 1 7908 -8 -35 1 7909 -9 -35 1 7910 -10 -35 1 7912 -12 -35 1 7915 -15 -35 1 7918 -18 -35 1 7924 -24 -40 1 Application Basic Parameters 33-Terminal -Terminal 11 A ive Voltage A Negat Negative Voltage Regulator Regulator 79xx 79xx V in 330 nF 100 nF 1 GND 2 IN 79xx 3 OUT 79xx- Typical Application V out 33-Terminal -Terminal 11 A ive Voltage A Negat Negative Voltage Regulator Regulator 79xx 79xx 20V 1 IN 7815 3 OUT 15V 2 GND 330 nF 100 nF 330 nF 100 nF 1 GND -20V 2 IN -15V 7915 3 OUT Split Power Supply (±15 V - 1 A) Three -Terminal Adjustable Three-Terminal Adjustable Regulator Regulator-- LM117, LM117, LM317 LM317 1 2 3 1 ADJ 2 Vin 3 Vout Parametr min V out [V] 1,2 I out [A] Vref [V] typical max 37 1,5 1,2 1,25 Application Basic Parameters 1,3 Three -Terminal Adjustable Three-Terminal Adjustable Regulator Regulator-- LM117, LM117, LM317 LM317 INPUT Error Amplifier Vref Current Limit ADJ Rlimit OUTPUT LM 117- Block Diagram Three -Terminal Adjustable Three-Terminal Adjustable Regulator Regulator-- LM117, LM117, LM317 LM317 3 Vin 2 Vout LM117 1 GND V in R1 240 V out 100 nF 1 uF R2 5k Uo = Uref (1 + R2 ), Uref = 1,25V R1 LM117- Typical Application Three -Terminal Adjustable Three-Terminal Adjustable Regulator Regulator-- LM117, LM117, LM317 LM317 3 Vin 2 Vout LM117 1 GND V in R1 150 V out 100 nF 1 uF R2 5k LM113 1,2V 680 -10V 0V-30V Regulator Low -Out Regulator: Low Drop Drop-Out Regulator: LDO LDO ∆U = Ui − Uo U T R1 Ui k + Uo R2 Uref Typical Regulator : ∆U > 2V LDO : ∆U = 0,2V ÷ 0,5V Low -Out Regulator: Low Drop Drop-Out Regulator: LDO LDO Low-dropout adjustable and fixed linear voltage regulator NX1117 [Source: www.npm.com] Functional Diagram [Source: pl.mouser.com] Low -Out Regulator: Low Drop Drop-Out Regulator: LDO LDO Typical application for fixed output voltage versions [Source: www.npx.com] Key applications -Post regulation for SMPS (Switched Mode Power Supply) -Consumer and industrial equipment -Battery charger -Hard drive controllers -Core voltage supply: FPGA, PLD, DSP, CPU -LCD TV -DVD player Switching Switching Regulators Regulators Linear regulator efficiences is about 40%. The larger the difference between the input and output voltage, the more heat is produced. Even the new LDO (low drop-out) regulators are still inefficient linear regulators. A switching regulator works by taking small chunks of energy. Practical switching regulator efficiences typically range from 70%-95%. The highest efiiciency is desired when battery life is critical. The lost power is dissipated as heat. Switching Switching Regulators Regulators Switch Low Pass Filter Vo Vi PWM Controller Filter Error Amplifier Block Diagram Vref Switching Switching Regulators Regulators UL L K Ut Uin D IL Io C Ro Uo Low Pass Filter Ut t on t off t Switch PWM Controll Step-Down Switching Regulator Switching Switching Regulators Regulators UL L Uin IL D On State UL L Io C Ro UL Uo IL Io C Uin Ro Uo Off State Uin-Uo t -U o IL IL = I o t ton toff Vo ton = Vin T ton Vo = Vin T L Uin Ut IL D K Vo T = Vin toff Io C Ro Uo T Vo = Vin toff Step-Up Switching Regulator LM2574 LM2574 Switching Switching Regulator Regulator ON/OFF Vin Feedback GND Output GND Block Diagram [Source: www.ti.com] LM2574 LM2574 Switching Switching Regulator Regulator Typical Application [Source: www.ti.com] LM2574 LM2574 Switching Switching Regulator Regulator Parameters -3.3V, 5V, 12V, 15V and Adjustable Output Version -Adjustable Output Version Voltage Range: 1.23V- 37V -Specified 0.5A Output Current -Wide Input Range: 40V -52kHz Fixed Fraquency Internal Oscillator -TTL Shutdown Capability, Low Power Standby Mode -High Efficiency -Thermal Shutdown and Current Limit Protection LM2574 LM2574 Switching Switching Regulator Regulator At low input voltages efficiency is degraded. Higher inputs make the fixed loss a smaller percentage, improving efficiency. LT1109 LT1109 Switching Switching Regulator Regulator Block Diagram [Source: http://cds.linear.com/] LT1109 LT1109 Switching Switching Regulator Regulator Typical Application [Source: http://cds.linear.com/] LT1109 LT1109 Switching Switching Regulator Regulator Parameters: Output Voltage: 5V, 12V, Adjustable Voltage 120kHz Oscillator 1.6V Mimimum Start-Up Vlotage Logic Controlled Shutdown Output Current 100mA (Output 5V), 60mA (output 12V) MC34063 MC34063 Switching Switching Regulator Regulator Step-Up/Down/Inverting Switching Regulator Block Diagram [Source: www.ti.com] MC34063 MC34063 Switching Switching Regulator Regulator Inverting Switching Regulator [Source: www.ti.com] MC34063 MC34063 Switching Switching Regulator Regulator Parameters: -Operation from 3V to 40V Input -Low Standbay Current -Current Limiting -Output Switch Current to 1,5A -Output Voltage Adjustable -Frequency Operation to 100kHz -Precision Reference 2A 2A Standard Standard Buck Buck PWM PWM Regulator Regulator ISL ISL 8500 8500 Functional Block Diagram 2A 2A Standard Standard Buck Buck PWM PWM Regulator Regulator ISL ISL 8500 8500 Typical Application Schematic 2A 2A Standard Standard Buck Buck PWM PWM Regulator Regulator ISL ISL 8500 8500 Parameters: Standard Buck Controller with Integrated Switching Power MOSFET Integrated Boot Diode Input Voltage Range: Fixed 5V ±10%, Variable 5.5V to 25V PWM Output Voltage Adjustable from 0.6V to 19V with Continuous Output Current up to 2A Fixed 500kHz Switching Frequency Output Undervoltage Protection Enable Inputs Overcurrent Protection, Thermal Overload Protection Internal 5V LDO regulator LM LM 317 317-- Switching Switching Regulator Regulator Low Cost 3A Switching Regulator [Source: www.ti.com] UA723 UA723-- Switching Switching Regulator Regulator [Source: www.ti.com] 78xx 78xx-- Switching Switching Regulator Regulator [Source: www.farichaldsemi.com]
