3 Replies Latest reply on Oct 7, 2019 8:42 AM by YatheeshK_36

    CCG3PA power delivery turn-around time

    JuOl_4441426

      We are developing for a CCG3PA in a dual-role hub type product.

       

      Currently, I am seeing about 100 – 300 ms power-down time on usb-c power when we switch between a tablet powering the bus vs the tablet being powered from the bus.  I know that FRS is available on other CYPD chips, but not the CCG3PA.  But, is there anything we can be doing to speed-up that turn around time?  We are hoping to keep USB peripherals that are connected to the hub alive during the change in power direction.  Thanks for any help.

        • 1. Re: CCG3PA power delivery turn-around time
          YatheeshK_36

          Hello,

           

          Do you have the cc logs for this. If yes please do share it.

          Can you please let me know which firmware you are using. Is it an example firmware or a custom one.

           

          Best Regards,

          Yatheesh

          • 2. Re: CCG3PA power delivery turn-around time
            JuOl_4441426

            Thanks Yatheesh.  Below is a link to my EZ-PD Analyzer capture.

            At 0 I plug a USB-C tablet into the powered dock.  The tablet starts charging.

            At 25 I un-power the dock with the tablet still plugged into the dock.  At this point, the tablet starts powering the dock.

            At 45 I re-power the dock. At this point, the tablet stops outputting power and then starts charging.

             

            https://drive.google.com/open?id=124AdYcaSO5ndD851zsrldqUiXfctUPuA

             

            When power is flipped, I see about a 100 - 300 ms down-time on the USB-C power bus.  This causes any peripherals on the dock to re-enumerate, which is not desirable.

             

            Thanks for any help!

            Justin

            • 3. Re: CCG3PA power delivery turn-around time
              YatheeshK_36

              Hello Justin,

               

              When the dock is powering the tablet and the power is removed from the dock then there will be a power shutdown which is expected, because the CCG3PA will put up a dead battery termination and then the PD contract is re-established.

              But when the CCG3PA is powered externally when the power is being drawn from the tablet, the CCG3PA should initiate a PR_SWAP to the port partner to become a source. Do you see the same behavior on different devices. Please do let me know which firmware you are using for the CCG3PA chip.

               

              Best Regards,

              Yatheesh