Application Examples Specifying the
Equipment-Sig
nal Quality Tests for High Speed Devices for Upstream Testing
Specifying the Equipment-Signal Quality Tests for High Speed Devices
for Upstream Testing
The following equipment is needed for signal quality tests on a High Speed device for upstream testing :
Tektronix digital oscilloscope
TDSUSB2 application
TDSUSBF complia
nce test fixture (Revision B)
One P6248
1
or P6330 differential probe
1
For best results, use 1X attenuation when using the P6248.
Typical Equipment Setup-Signal Quality Tests for High Speed Devices
for Upstream Testing
To set up the equipment for the High Speed Signal Quality test, follow these steps:
1. Set the S6 switch to the Init position.
2. Connect the standard USB cable between the Device SQ Init port a nd the host port.
3. Connect the USB cable from the A receptacle (marked DUT) of the D evice SQ test port of the test
fixture to the unit under test (device).
4. Configure the measurement and select the
command button to run the a pplication.
5. Place the device in the test mode Test_Packet from the host controller.
6. Set the test Init switch to the test position to isolate the unit under test while maintaining the bus power.
7. Select OK after acquiring a waveform. Verify that it is a correct waveform.
If the signal is clipped, follow these st
eps to increase the vertical scale:
1. In the oscilloscope menu, select Vertical >Vertical Setup to display the Channe l screen.
2. In the Scale field, increase the vertical scale values until the w aveform is completely displayed in
the screen.
TDSUSB2 Universal Serial Bus Measurements Package 87
To Next Page
Loading...
Need help?
General
