AM6442: USB Compliance fail

Hi Martin,

I am routing your query to our USB hardware expert for comments.

Hello Martin,

Thank you for the query.

Can you confirm if these eye diagram results are post-processed by the USB Electrical Test Tool? It is the only way to determine true pass/fail.

https://www.usb.org/document-library/usbet20

Regards,

Sreenivasa

Hello Sreenivasa

The measurement was made with LeCroy QualiPHY. I just did another measurement and used the USB Electrical Test Tool to analyze the results. Looks a little bit better but still fails. 

Regards

Martin

Hello Martin, 

Thank you for the inputs.

Are you testing this on the EVM or a custom board.

If this is a custom board, have you had a chance to test on the EVM.

If this is a customer board, help me understand the USB interface implementation.

Regards,

Sreenivasa

Hello Sreenivasa

It is a custom board. See the attached PDF for schematic.

The Common Mode Choke (L700) is a Murata DLM11SN900HY2

NEA_USB.pdf

Regards

Martin

Hello Marting.

Thank you for the inputs.

Are all the USB connections on the same board.

Pls help me understand the point where the measurements are being done.

Regards,

Sreenivasa