Hub Upstream Signal Quality Testing
4
DSOX4USBSQ USB 2.0 Signal Quality Analysis Application Electrical Testing Notes
57
Hub Upstream Hi-Speed Connection - Differential Probe
Perform these connection steps:
1
Attach the 5V power supply to J5 of the E2649- 66401 Device Hi- Speed
Signal Quality test fixture.
Leave the TEST switch at the OFF position.
Verify green POWER LED is lit, and yellow TEST LED is off.
2
Connect the [TEST PORT] of the test fixture into the upstream facing
port of the hub under test, using the 4" USB cable.
3
Connect the [INIT PORT] of the test fixture to a hi- speed port of the
Test Bed Computer. Apply power to the hub.
4
Attach the Agilent 113xA differential probe to D+/D- of TP2 on the test
fixture. Ensure the + polarity on the probe lines up with D+ on the
fixture.
5
Please terminate the fixture's SMA connectors with 50 Ohm
terminators.
1
2
3
4
Hi-Speed Host
5m Cable
Hub Under Test
upstream
port
4“
Init. Port
Test
Port
5V
D+
D-
TP2
Device
Hi-Speed
Signal Quality
Test Fixture
113xA
differential
probe