Eye Doctor Datasheet

EYE DOCTOR™
Leading Features
• Full signal integrity analysis
of equalized receiver signal
• Real time co-simulation
of measured signals and
measured or modeled network
characteristics
• Performance margin analysis
in equalized systems
• De-embedding of fixture and
probe responses
• High accuracy far-end channel
measurements
• Emulates any combination of
DFE and FFE equalizers
• Automatic equalizer coefficient
optimization
• Direct entry of FFE and DFE
coefficients
Virtual Probing™ and equalizer emulation enhance the capability of the SDA to allow
the measurement of serial data signals in equalized systems
have increased, the measurement
Measuring Equalized
Systems
challenges have also and with the
Imperfections such as through
adoption of receiver equalization,
holes, connectors, vias and package
traditional jitter and noise measure-
pins cause distortions in the high
ments are becoming inadequate
frequency content of high bit rate
for determining interoperability.
signals. The resulting eye is often
Eye Doctor™ is a DSO-based
closed or nearly closed. The tradi-
instrumentation and simulation
tional approach to interoperability
system which addresses these
testing involves measuring the
measurement challenges and is
channel response and the transmit-
a dramatic leap in interoperability
ter signal quality against compliance
and compliance testing capability.
masks designed so that the signal
As the symbol rates of systems
Eye Doctor provides the tools to
undo or compensate many common
forms of distortion thereby increasing signal to noise, opening eyes,
increasing rise time, reducing jitter
restoring lost bandwidth and improving waveform fidelity.
eye and jitter will enable error-free
operation. In an equalized system,
the channel, transmitter and receiver
are closely coupled and interoperability is determined by whether the
signal can be equalized. What is
needed is a method to quantitatively
measure the interoperability of
these systems.
Tools for Next Generation Serial Data Analysis
Current generation serial data systems ensure interoperability using compliance measurements. Next generation systems employing
equalization require new methods for determining interoperability. With the signal eye closed, traditional compliance measurements
are no longer sufficient.
Eye Doctor
Virtual Probing
available, usually at the transmitter,
Eye doctor consists of two
Probes and fixtures are not perfect
and the corrupted signal at the
elements; Virtual Probing™ and
and their presence in the circuit
far-end of the channel (at the end
equalized receiver emulation.
impacts both the loading on the
of the backplane) can be simulated
Virtual Probing enhances the
DUT as well as the waveform seen
thus eliminating probe and instru-
accuracy of measurements
by the oscilloscope. Virtual Probing
ment noise from the measurement.
made on distorted waveforms
is a powerful signal processing tool
The derived filter takes into account
while equalized receiver emulation
which enables the user to measure
all of the interactions among the
allows measurements to be made
a signal anywhere within a system
elements of the system and trans-
from a “receivers eye view.”
and then project a response at any
mitter signal including differential
The ideal view of the signal within
other desired point. This feature
to common mode conversion, near-
the receiver allows accurate total
works by using S-parameter files
end and far-end crosstalk.
jitter and bit error rate measurements
of the various components in the
Virtual Probing can be used to
that are representative of actual
system to derive a filter which
de-embed probe and fixture responses
system performance.
relates the desired measured signal
from measurements thereby improv-
to the acquired waveform. For
ing the accuracy of signal integrity
example, measurements can be
measurements.
made where the cleanest signal is
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Equalizer Emulation
Eye Doctor features equalized receiver
emulation which includes both Feed
Forward Equalization (FFE) and Decision
Feedback Equalization (DFE) along with
clock recovery and a variable decision
Equalizer emulation simulates the signal as viewed within the receiver.
The component can automatically determine the optimum weighting
coefficients for both FFE and DFE with the number of taps for each
selected by the user. Coefficients can also be entered directly. The full
jitter analysis capability of the SDA is available on the equalized signal.
threshold. This ideal receiver reveals
the signal as seen within a real receiver
at the detector where it is impossible
to probe. The equalized signal can be
measured using the powerful jitter and
signal analysis software in the SDA
allowing the bit error rate, total jitter,
and eye opening to be measured thus
giving a precise indication of the
performance margin. Because the
receiver emulation is ideal, the margins
are measured independently of measurement system and receiver noise.
Virtual Probing simulates signals from any point within the system using a single
measured waveform. The virtual probe shown here is co-simulating a backplane
which closes the eye. The equalizer corrects the distortion caused by the backplane which opens the eye. The Processing Web Editor is used to connect the
equalizer and Virtual Probing elements in an intuitive signal flow diagram layout.
3
Specifications
Equalizer Emulation
Virtual Probing
• Up to 20 tap linear tapped delay line equalizer
(transversal filter).
• Provides waveforms that compensate for probe loading
effects within bandwidth limitations of the system.
• PLL for clock recovery with variable loop bandwidth.
• Produces linear filters that operate on up to 8 inputs
and provides up to 8 outputs.
• Up to 20 tap Decision Feedback Equalizer (DFE)
including erasure DFE.
• Simple text file system description similar to Spice.
• Accepts Touchstone format S-parameter file network
device descriptions.
• Clock skew adjustment.
• Outputs for equalized waveform (slicer input),
data waveform (slicer output), and recovered clock.
• Includes simple device descriptions such as ideal tees,
power splitter, open, short, thru plus lumped elements
such as resistors, capacitors and inductors.
• Error waveform output for user defined equalizer
optimizations.
• Automatic blind adaptation using built-in LMS
algorithms.
• Multi-level detection threshold supports duobinary
and multilevel signaling systems.
Ordering Information
Customer Service
Eye Doctor is optional on the following SDA and
WaveExpert models
• Serial Data Analyzers SDA 6000A, SDA 6020, SDA 9000,
SDA 11000, SDA 18000
• SDA 100G, NRO 9000 and WaveExpert 100H
Product Description
Eye Doctor (Virtual probe and
equalizer emulation bundle)
Virtual Probe
Equalizer Emulation
Retrofit Kit for Eye Doctor (Virtual probe and
equalizer emulation bundle)
Retrofit Kit for Virtual Probe
Retrofit Kit for Equalizer Emulation
Product Code
EYEDR
EYEDR-VP
EYEDR-EQ
LeCroy oscilloscopes are designed, built, and tested to ensure
high reliability. In the unlikely event you experience difficulties,
the WaveExpert Series oscilloscopes and modules are warranted
for a period of one year, and our probes are warranted for one year.
The SDA Series Serial Data Analyzers are fully warranted for
three years.
This warranty includes:
• No charge for return shipping
• Long-term 7-year support
• Upgrade to latest software at no charge
RK-EYEDR
RK-EYEDR-VP
RK-EYEDR-EQ
1-800-5-LeCroy
www.lecroy.com
Local sales offices are located throughout the world.
To find the most convenient one visit www.lecroy.com
© 2007 by LeCroy Corporation. All rights reserved. Specifications, prices, availability, and delivery subject to change
without notice. Product or brand names are trademarks or requested trademarks of their respective holders.
EyeDrDS_W2_10July07