Connect-Tek USB-16 Manual de usuario descargar pdf (Pagina 25)

Host High Speed Electrical Test Procedure Revision 1.4

4.6 Host Disconnect Detect (EL_36, EL_37)

This section uses the Disconnect test fixture to verify the disconnect thresholds of the port under

test by simulated disconnect condition. (Contact the USB-IF to acquire this fixture. The TDSUSBF

test fixture does not support this test.)

When the TEST switch on the test fixture is in the Test position, the port under test is subjected to

a threshold < 525 mV. The port should not detect a disconnection.

When the TEST switch is in the Normal position, the port under test is subjected to a threshold

> 625 mV. The port should detect a disconnection.

1. Attach the 5 V power supply to Disconnect test fixture (J8).

2. Attach the differential probe to J7. Ensure the + tip on probe lines up with D+ on the fixture.

Recall the DISCDETE.SET oscilloscope setup.

3. Set the TEST switch to the Test position. Verify that the green Power LED (D1) is lit, and the

yellow Test LED (D2) is also lit. This sets the test fixture to emulate a must-not-disconnect

threshold.

4. Attach the Test port of the test fixture to the port under test. In the Host Test menu of the High-

speed Electrical Test Tool software select TEST_FORCE_ENABLE from the Port Control

window. Enter the port number and click Execute once and in the Status Window ensure that

the operation is successful.

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Connect-Tek USB-16 Manual de usuario Pagina 25