Technical data

66 DSOX4USBSQ USB 2.0 Signal Quality Analysis Application Electrical Testing Notes
5 Hub Downstream Signal Quality Testing
Hub Downstream Hi-Speed Signal Quality Test
To set up and run the Hub downstream Hi- Speed signal quality tests:
1 Connect the USB Device, test fixtures, and equipment:
• If you are probing the test fixture using a differential probe, see
"Hub Downstream Hi- Speed Connection - Differential Probe" on
page 69.
• If you are probing the test fixture using SMA cables, see "Hub
Downstream Hi- Speed Connection - SMA Cables" on page 70.
2 Set up the test signal/packet that will be analyzed.
To set up the test packets used for compliance testing, see "Hub
Downstream Hi- Speed Compliance Test Packets" on page 71.
3 On the oscilloscope's front panel, press the [Analyze] key.
4 In the Analyze Menu, press the Features softkey; then, select USB Signal
Quality.
5 Press the Te st softkey and select the Host Hi-Speed Signal Quality test.
6 Press the Signals softkey. In the USB Signal Quality Signals Menu:
a Press the Test Connection softkey and select whether you are using a
Single-ended (with SMA cables) or Differential probe connection.
b If you are using a differential connection, press the Source softkey
and select the analog input source channel connected to the
differential probe.
Table 11 Equipment Used in Hub Hi-Speed Signal Quality Test - Downstream Facing Ports
Quantity Item Description/Model
1 Oscilloscope Agilent 4000 X-Series 1.5 GHz bandwidth
model
1 Oscilloscope probing solution:
• Differential probe Agilent 113xA with E2678A or E2669A
• SMA cables Agilent 15443A matched cable pair or
equivalent
1 Host test bed computer Any computer with the Windows XP,
Windows 7, or Windows 8 operating system
and hi-speed USB ports.
1 Host Hi-Speed Signal Quality test
fixture and 4" USB cable
Agilent E2649-66402
1 5V power supply Agilent 0950-2546 or equivalent