Specifications

87
Chapter 3: Testing Performance
Test Pod 1 in the 1500 Mb/s mode
Adjust the measured pulse width to 600 ps
In this procedure, you will use the oscilloscope’s measurement markers to
measure the actual pulse width in the test setup. Then you will adjust the pulse
generator so that the measured pulse width is as specified.
9 Observe the 54845A oscilloscope display. Change the Channel 2 pulse
width of the 8133A pulse generator so that the pulse width measured at 1
volt on the oscilloscope is equal to 600 ps minus the measurement
uncertainty and display resolution of the oscilloscope, further reduced by
35 ps for test margin.
If you are using the 54845A/B oscilloscope, the measurement uncertainty
is ±((0.007% * ∆t) + (full scale/2x memory depth) + 30 ps) ≅ ±30 ps. Add
5 ps for display resolution. Add 35 ps test margin.
600 ps - 30 ps - 5 ps - 35 ps = 530 ps. Set the pulse width as measured on
the 54845A/B oscilloscope to 530 ps.
In the oscilloscope horizontal setup, change the position to 300 ps (or as
required) to center the pulse on the display.
On the oscilloscope move the Ax and Bx markers to the crossing points of
the pulse and the horizontal center line. Read the pulse width at the