Teledyne LeCroy QPHY-USB - Manual (Page 40)

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QPHY-USB Operator’s Manual Rev F
HUB HIGH-SPEED DOWNSTREAM REPEATER
Figure 41. Hub and Device Fixture Connections for Downstream Repeater Test
1. Select Hub in the Mode control and HS Downstream Repeater in the Test control in the USB Test
Wizard.
Note: Longer cables and/or adapters may be used to ease connection of Mini-B and Micro-B connectors.
2. Follow the instructions in the USB Test Wizard to acquire the waveforms as shown:
Figure 42. Hub downstream repeater delay
The measured time delay between input and output sync fields should be less than 36 bits plus 4 ns (< 79 ns).
The 4 ns are added to account for the delay through the fixture.
To host computer
To hub upstream port To hub downstream port
To certified High-Speed
device