Teledyne LeCroy SDA III-CompleteLinQ - Manual (Page 37)

Operator's Manual
Eye Patterns
SDAIII-CompleteLinQmeasures eye patterns without using a trigger. This is done using the software clock
recovery (discussed in
Set Up Clock Recovery ) to divide the data record into segments along the time
values of the clock. For the purpose of dividing the time line into segments, the time resolution is essen-
tially infinite. The samples occur at fixed intervals of 25 or 50 ps/pt (for 40 or 20 GS/s sampling rate). The
samples are positioned relative to the recovered clock edge times, and the segments delimited by the
clock (the unit intervals or bits) are overlayed by aligning the clock delimited boundaries.. A monochrome
or color persistence display is used to show the distribution of the eye pattern data. Since the unit inteval
are determined from the recovered clock and not from the oscilloscope's trigger position, this method
does not include jitter from any trigger circuit.
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