Hi Expert,
The engineer is evaluating the output performance, and mentioned why high level not meet 475~525mV range.
Can you help to check the waveforms and schematic design:
Thanks
Eric
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Hi Eric,
Can you provide a voltage measurement of the 3.3V rail at the pin of the TUSB2E22? The eye mask template you shared is for a device (without a captive cable) at TP3. I will try and reproduce your results.
Regards,
Nicholaus
Hi Eric,
I had no issue meeting the eye mask defined in the HS eye mask test. Does your test setup match the USB 2.0 Device High-Speed Signal Quality test?
USB 2.0 Electrical Compliance Test Specification Version 1.07 | USB-IF
Regards,
Nicholaus
Hello Nicholaus,
Thanks for your support.
This is the engineer fist time to use TUSB2E22,and they are not going the USB 2.0 Electrical Compliance Test Specification Version 1.07 | USB-IF.
They want to go the system level testing, and their testing engineer want to know how to validate the TUSB2E22.
Due to the EVM not disclosed the output performance, can you advice any easy testing can be used to judge the TUSB2E22 performance is working under expectation ?
And what is expected result will had?
Thanks
Eric
Hi Eric,
If the customer is doing their own system testing, then they can determine what passing or failing condition is for their test. The eye mask presented in the specification doesn't apply unless the customer also follows the test setup in the specification. This is because the amplitude and jitter for the USB signal will vary based on how long the channel length (cable, PCB trace, etc) is, what connectors are in the signal path, passive components, vias, etc.
I can assure you the TUSB2E22 is fully compliant to the eUSB repeater specification and, assuming it is not damaged, is operating as it should. Our group helped write the specification for eUSB repeaters, the TUSB2E22 was the industry's first eUSB repeater, and it is the most popular repeater in-use today.
Can you describe the test setup? The test setup for the official test would be:
Host->4" USB cable->USB Test Fixture->Oscilloscope
Regards,
Nicholaus
Hi Nicholaus,
Thanks and sorry to brother you.
May we use the general eye diagram as spec to check the TUSB2E22 performance?
Thanks
Eric
Hi Eric,
An eye diagram is great for determining general performance/signal quality of a system. These images you have provided look good, and the eye is open.
However, claims made about the TUSB2E22 electrical performance would need to an official test setup, anything else would be considered informative.
Regards,
Nicholaus