This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMUXHS221: eye diagram issue

Part Number: TMUXHS221
Other Parts Discussed in Thread: TUSB211A

Hi team,

This is a problem one of our customers is experiencing, could you please provide some troubleshooting suggestions?

When using the TMUXHS221 chip as the USB2.0 switch, it was found that the signal after passing TMUXHS221, there is an obvious collapse in the middle of the eye diagram, causing the eye diagram to cover the eye pattern , would like to ask, What is the cause of the collapse here, and are there any measures to improve it?

Best Regards,

Amy Luo

  • Hi Amy,

    The current issue seems to be related to the return loss of the mux, which is something that cannot really be changed unfortunately.

    Looking at the eye, the best recommendations I have would be to incorporate a TUSB21X redriver, such as the TUSB211A, and set it to the lowest boost settings to better the AC timings of the signal, or to look at the trace of the signal, and see where it can be shortened to reduce the amount of loss in the trace.

    Please let me know if you have any other questions.