Teledyne LeCroy QPHY-USB3-Tx-Rx - Manual (Page 30)

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917719 Rev A
At the completion of the Phase Jitter Slew Rate Test the oscilloscope is in the following configuration:
Figure 17 - Oscilloscope Configuration after Phase Jitter Slew Rate Test
On this screen there are 2 traces visible. These are the PLLTrack of the captured waveform and the first
derivative of the PLLTrack is show in F1.
The minimum and maximum of the derivative of the PLL Track is measured in P1 and P2. The Tj, Rj and Dj value
are also on by default when looking at any jitter trace (the PLL Track in this case).
Figure 18 - Test Report from Phase Jitter Slew Rate Test
Test 1.3.3 SigTest Jitter
The purpose of this test group is to verify that the jitter is within the specification limits using the SigTest DLL
provided by the USB-IF and integrated into the oscilloscope software. The test is performed in the same manner
that Test 1.3.1 is performed, with the exception of that the SigTest DLL is used for analysis, not the SDA II
software. For compliance testing the measurements are made after a compliance channel after applying the
reference Continuous Time Linear Equalizer function. The SigTest DLL currently implements the CTLE function,
however, it does not implement the channel emulation. For this reason, the channel emulation is still performed in
Eye Doctor II before the signal is seen by SigTest . Measuring the jitter is a multiple step process. First, the jitter
must be measured while the PUT is transmitting the CP1 (101010) pattern. Then, the jitter is measured while the
PUT is transmitting the CP 0 (scrambled D0.0) pattern, however the Rj that was measured during the jitter test of
CP1 must be injected into this measurement. This simplifies the separation of Rj and Dj since there is no DDj
when CP 1 is transmitted.