User guide

• Connect the N4903B’s Trigger Output with the oscilloscope’s Front panel
Trigger input
• Connect the N4916B’s Data Output with channel 1 of the oscilloscope
• Terminate the N4916B’s complement output using a 50Ohm termination
resistor
1
N4903B
a
Open the configuration page for external instruments
b
Enable the De-Emphasis function
c
Click the Load Calibration Setting… button
d
Set the PG’s data rate to 14.2 Gb/s
e
Open the external instruments configuration screen again
2
86100A
a
Enable Channel 1, set the vertical scale to 100 mV/div and the offset voltage
to 0 V
b
Select the appropriate trigger input and set the threshold voltage to 0 V.
Select Trigger Mode ‘Normal’ (DC – 2.5 GHz)
c
Set the time base to 28.2 ps
d
Adjust the Delay to show the start of the 2
7
-1 PRBS at the center of the
screen (0000001111111 bit sequence)
e
Set the Waveform Persistence to infinite
f
Enable Eye Mask Mode
For each Input Timing Setting (1 to 6) execute the following steps:
• Set the Input Timing on the N4903B
• Clear the oscilloscope’s display
• Wait for waveforms to accumulate for approximately 6 minutes
• Check the waveform on the oscilloscope for erroneous measurements that
indicate a timing violation at the input of the N4916B
When all 6 settings have been measured, select the optimum input timing setting
(keep in mind that one erroneous sample on the screen has to be treated as an
error).
Example screen shots
• Input Timing Setup = 1
Solving Problems 9
Agilent J-BERT N4903B High-Performance Serial BERT 485
Calibration Preparation
Calibration Sequence