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
Test
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
