Teledyne LeCroy QPHY-BroadR-Reach - Manual (Page 24)

Test 3- Transmitter Jitter (Slave) and Transmit Clock Frequency
This test measures slave jitter, TX_TCLK, as specified in Section 5.4.3 and the transmit clock frequency
as specified in Section 5.4.5. This test requires that the Slave is receiving valid signals from a compliant
PHY operating as the Master and is configured as shown below. This test requires the DUT to be placed
in test mode 3.
Figure 16 – Transmitter Jitter (Slave) and Transmit Clock Frequency Setup
What is Measured:
The oscilloscope captures a 1 ms acquisition at 10 GS/s relative to an unjittered reference resulting in 10
Mpts. By sampling in this manner, very low frequency components are filtered out. The RMS of
TX_TCLK is then calculated and should be less than 0.01 UI. Using the same acquired signal the symbol
rate is also measured. Additionally, the rise and fall times are calculated for informational purposes.
Test Methodology:
The oscilloscope is set to acquire 10 Mpts at 10 GS/s. The acquired signal has two bits of enhanced
resolution (ERES) applied to it in order to limit the bandwidth of the oscilloscope to a value which is
suitable for this measurement. The RMS value of the jitter track for the acquired signal is calculated. The
calculated value is then compared to 0.01 UI using pass/fail testing. The bit rate (half of the symbol rate)
of the acquired signal is also measured and the compared to 33.3 MHz +/- 50 ppm using pass/fail testing.
Lastly, the 10%-90% rise and fall times are calculated for information purposes.
24 922533 Rev B