2 Replies Latest reply on Mar 26, 2020 1:15 PM by PaRi_1293246

    CYPD3125 - DRP Application - Questions

    PaRi_1293246

      Hello,

       

      We have selected the CYPD3125 to implemented a USB Type-C DRP on our latest portable scanner.

       

      We have some questions that need to be answered before we can finalize the schematic.

       

      - Is the external reset XRES require an external pull-up resistor like on the evaluation board? If yes, what value?

      - Is the display port hot plug detect HOTPLUG_DET require an external pull-up resistor like on the evaluation board? Is the output open drain?

      - Is the producer VBUS gates driver VBUS_P_CTRL0 and VBUS_P_CTRL1 are interchangeable? Do they have the same timing?

      - Is the consumer VBUS gates driver VBUS_C_CTRL0 and VBUS_C_CTRL1 are interchangeable? Do they have the same timing?

      - On the evaluation board display port AUX_P/AUX_N are going through the high speed MUX PS8740B before going through the CYPD3125. Why those signals are going through the CYPD3125 and not directly from the PS8740B to the USB connector?

       

      Thank you

       

      Best Regards,

       

      Patrice

        • 1. Re: CYPD3125 - DRP Application - Questions
          ShifangZ_26

          Hi Patrice,

           

          Kindly refer my comments as beliw:

          - Is the external reset XRES require an external pull-up resistor like on the evaluation board? If yes, what value?

          >> Yes. Please refer below schematic from CY4531 (CCG3 kit) hardware schematic.

          - Is the display port hot plug detect HOTPLUG_DET require an external pull-up resistor like on the evaluation board? Is the output open drain?

          >> If you are using CY3125, by default, the firmware is DisplayPort source, which is meant of the HOTPLUG_DET is output.

          If you are designing a DisplayPort sink design, you should follow the reference

          Type-C plug design: https://www.cypress.com/documentation/reference-designs/ez-pd-ccg3-usb-type-c-displayport-cable-solution

          Type-C receptacle design: CCG3 Type-C receptacle DRP Reference Design (Power source & DisplayPort Sink)

          And the external resistor is pull-down with 100K.

           

          - Is the producer VBUS gates driver VBUS_P_CTRL0 and VBUS_P_CTRL1 are interchangeable? Do they have the same timing?

          >> Yes. It is interchangeable. They do not have same time, there are 10us (by default) delay between VBUS_P_CTRL0 and VBUS_P_CTRL1.

           

          - Is the consumer VBUS gates driver VBUS_C_CTRL0 and VBUS_C_CTRL1 are interchangeable? Do they have the same timing?

          Yes. It is interchangeable. They do not have same time, there are 10us (by default) delay between VBUS_C_CTRL0 and VBUS_C_CTRL1.

           

          - On the evaluation board display port AUX_P/AUX_N are going through the high speed MUX PS8740B before going through the CYPD3125. Why those signals are going through the CYPD3125 and not directly from the PS8740B to the USB connector?

          >> Since PS8740B and CYPD3125 have internal MUX for SBU1/2 channel. You just need use one of them. You also can go through PS8742 and by-pass CCG3.

           

          Best Regards,

          Lisa

          • 2. Re: CYPD3125 - DRP Application - Questions
            PaRi_1293246

            Hi Lisa,

             

            Thank you very much.

             

            Best Regards,

            Patrice