Teledyne LeCroy SDA III-CompleteLinQ - Manual (Page 38)

SDAIII-CompleteLinQ Software
Jitter Measurements
Set Up Jitter Measurements
Touch the Setup Jitter Measurements button on the Serial Data Analysis II dialog to access the Jitter
Measure dialog. The SDAII jitter analysis follows a flow of events.
The main Jitter Measure dialog shows the basic flow of the jitter analysis through a simple block diagram
progressing from left to right. Each block in the diagram is also a button. Touching any of the buttons
opens its corresponding right hand dialog.
Jitter Measurements flow diagram dialog
SDAII jitter analysis techniques are described in the following topics. The main parts of this flow cor-
respond to the block diagram on the main Jitter Measure dialog.
A comprehensive white paper describing how jitter is measured, SDAIII Jitter Calculation Methods, on
the Teledyne LeCroy website.
Enable Jitter Measure
If this checkbox is unchecked, it turns off all traces and parameters. However, the setup remains in effect.
When checked, the traces and parameters remain unchanged.
TIE Trend
NOTE: There is no block or button for TIE Trend on the dialog. However, the TIE trend is calculated in the
background.
First, the TIE trend is calculated, which is the deviation of each edge from the ideal provided by the recov-
ered clock. See
Set Up Clock Recovery .
Jitter Filter
1. The TIE trend, which only has a sample for each edge in the input waveform, is converted to what we
call a track or TIETrack, which is uniformly sampled at every UI, by inserting interpolated samples for
each UI where there was no edge (virtual edge). The track is also given a time axis. The TIE can now be
filtered.
2. This step allows a bandpass filter be applied to the TIETrack. Use the Filter Mode to turn the function
On or Off. You can specify a Low Pass Cutoff, High Pass Cutoff, and a Transition Width.
3. Any Jitter filtered from the Jitter Track at this point is not passed on to any of the downstream anal-
ysis.
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