1 Reply Latest reply on Jul 24, 2019 1:36 AM by SananyaM_56

    vbuspwr of cy7c65630


      Dear Support,


      in one of our design, we forgot to connect vbuspopwer to the upstream power bus and let it float.  seems it works fine most of the time. but we do once a while finding the device not identified by the PC. is these two observations have a connection?


      Appreciate your help.




      David Sun

        • 1. Re: vbuspwr of cy7c65630

          Hello David,


          The VBUS from upstream connector should be connected to the hub since that is needed for putting up D+/D- terminations and hence detection of the hub on the host. You could connect it to external power supply before the host is connected as well but it should not be left floating. It may be possible that the voltage crosses VIH for VBUSPOWER at certain instances when left floating which allows detection.


          Best Regards,