Technical data

124 U7232A DisplayPort Compliance Testing Notes
13 Source AC Common Mode Noise Tests
AC Common Mode Noise Test
The AC common mode noise measurement of the distributed clock network
verifies that the nominal operating clock frequency is within the
Acceptable tolerance range. In order for sink devices to properly recover
the data, the source clock must operate within the Acceptable tolerance
range.
The test must be made at all bit rates supported by the device under test
without pre- emphasis and a voltage swing of 1.2 volts. A test pattern of
D10.2 should be used.
Test P ro ce du re
1 Start the automated testing application as described in “Starting the
DisplayPort Electrical Performance Compliance Test Application" on
page 18.
2 Connect the W2641A test fixture to the device under test (DUT).
3 If you are using one connection, connect the probe to any channel. If
you are using two connections, connect the two probes to any two
channels of the oscilloscope. If you are using four connections, connect
the four probes to any four channels of the oscilloscope.
4 Connect the SMA to SMP cable to the SMA probe head of one of the
probes and to the data lane connector on the W2641A fixture that you
want to test.
5 Connect the other SMA to SMP cable to the other SMA probe head and
to the data lane on the W2641A test fixture that you want to test.
6 In the DisplayPort Compliance Test Application, click the Set Up tab.
7 Set the DUT Definition Driven Setting, the Test Type, the Fixture Type,
Lane- Channel Selection, Connection Settings, and the Connection Type
according to the type of testing being done.