Keysight E6961A, User Manual And Method Of Implementation

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Overview 1
Keysight E6961A User Guide and Method of Implementation 25
Test Mode 1. Output Droop Tests
Test Setup
This test may be run using either a two oscilloscope channels or a single
differential probe from the transmitter (MDI). Refer to “General Test Setup” on
page 14 for connection details.
Specification References
[1]
BroadR-Reach Physical Layer Transceiver Specification, v3.2, Section 5.4.1.
Transmitter Output Droop Positive Test Information
This test measures the positive output droop of the transmitter.
Reference
[1] specifies the positive output droop of a compliant PHY. The positive
droop measured with respect to the initial peak value after the zero crossing and
the value 500 ns after the initial peak, shall be less than 45%.
The application triggers the Test Mode 1 signal on the rising edge and determines
the time the positive peak occurred and the voltage at that specific instance. The
application then measures the voltage 500 ns after the peak. The Droop is
calculated as:
Droop = 100 X (Vd/Vpk)%
Where:
– Vd is the magnitude of the droop.
– Vpk is the initial peak after the zero crossing.
NOTE
Use the software supplied with your transmitter PHY to control the Device Under
Test.