Teledyne LeCroy QPHY-USB - Manual (Page 61)

QPHY-USB Software Option
QPHY-USB Operator’s Manual Rev F
61
Device and Hub Full-Speed Upstream Signal Quality Test
Upstream signal quality is tested for both hubs and devices and at both Full- and Low-Speed. USB 2.0 devices
require only the Full-Speed mode to be tested. The following setup is used in all cases (Full-Speed setup is
shown, Low-Speed is similar). The device or hub under test is connected to the last hub in the chain through the
Inrush section of the Test Fixture. A second device is connected to the hub through the Trigger section of the Test
Fixture. The second device must be a Low-Speed device for Low-Speed testing or a Full-Speed device for Full-
Speed testing. For Low-Speed testing C1 is connected to D- (J26D). The chain of hubs is intended to test the
receiver sensitivity of the hub or device.
Figure 63. Device Full-Speed Upstream Signal Quality Test Equipment Setup