• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 324 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

TPS65987D: Getting sudden Port Detach

Christian Wern56
Prodigy 190 points
Part Number: TPS65987D


Hello,

we have a TPS65978D in use in one of our products. We have a problem with sudden port detach events.

We tracked it down to a capacity and a common-mode-choke which we use in the output circuit of the TPS.

See the attached snippet of the output circuit. In case of detach I can see the overcurrent flag is set in the UCSI - GET_ERROR_STATUS command. However we cannot measure any increase in voltage or current at the output.

If the CMC L902 and the capacitor C915 are removed from the layout we don't see the sudden port detach events. 

Is this a known problem? Is our approach a valid solution to the problem?

Thanks,

Chris

  • 0
    TI__Mastermind 30000 points

    Hello Christian,

    I have not seen a common mode choke used to filter out noise on VBUS. Instead I have seen customers, as well as our EVMs use ferrite beads instead. You can refer to the TPS65988EVM for a proven ferrite solution.

    As far as your capacitance, the maximum capacitance allowed on VBUS following the Type-C PD spec is 10uF. So that is another potential issue that could explain the sudden port detach events