Teledyne LeCroy QPHY-ENET - Manual (Page 66)

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QPHY-ENET Operator’s Manual Rev G
1000Base-T Common Mode Output Voltage Test
This test ensures that the peak-to-peak common mode output voltage at the MDI is within conformance limits.
The peak-to-peak common mode output voltage is measured as the worst-case minimum to worst-case maximum
common mode output voltage. This test does not use a high-pass filter. This measurement is made for 4 pairs
(A,B,C,D) by changing J35, J36, J37, J38 jumper pins.
Figure 52. Fixture setup for Common Mode Output Voltage
1. Connect DUT to J67 and connect oscilloscope Channel 2 to J2.
2. Measure each Pair by changing Jumpers (A: J35, B: J36, C: J37, D: J38).
3. The transmitter signal must be less than 50 mV to pass the test.