Specifications

11-7
Performance Tests
Introduction
5. On the scope DELTA T menu, set the START MARKER to the crossover of the V
marker on the 90% level of the falling edge (midway into the edge noise or jitter). Set
the STOP MARKER to the crossover of the V marker at the 10% level (midway into
the edge noise or jitter).
6. Read the DELTA T value from the bottom of the scope display. Enter this value of
DATA FALLTIME on the Calibration Data sheet.
Data (inverted) Jitter
1. Perform the Preliminary setup if this has not already been done.
2. Use the scope timebase delay to view 8 sequential “EYE CROSSOVER”s. Use the
worst jittered eye crossover to perform the remainder of this procedure.
3. Center the eye crossover in the middle of the display. The scope timebase delay shown
at the top of the display should be in the region of 18 ns. It must not be near 16 ns as a
discontinuity in the scope occurs at this value and may cause measuring anomalies.
4. Select the scope MORE followed by HISTOGRAM menu and the SOURCE to
Channel 3.
5. Select VOLTS Histogram and move the WINDOW MARKERS 1 and 2 as shown in
Figure 11-3.
Figure 11-3
6. Press the AQUIRE key on the scope, set the number of samples to 1000 and then press
the START AQUIRING key on the scope (the acquisition progress can be observed at
the top right hand side of the scope display as an increasing percentage value).
7. Note the histogram which has been plotted. The peak of this histogram defines the
voltage level where the “EYE CROSSOVER” occurs. Record this voltage level.
8. Press the upper right key on the scope to show WINDOW and select Time histogram.
Locate the START marker approximately 20 mV below the EYE CROSSOVER and
the STOP marker approximately 20 mV above the EYE CROSSOVER.