3 Replies Latest reply on Jun 10, 2020 9:45 PM by YiZ_31

    BCR (CYPD-3177) and USB Type-A charging ports

    ScottK_91

      Hello,

       

      It is understood that the CYPD-3177 (BCR) does not support legacy or PPS charging profiles. 

       

      If the BCR enabled product is resistor set for 5V@2A and is plugged into various charging options below, what would be present on the BCR output, or at the FAULT pin?

       

      USB Ports on Laptops using Type-A to Type-C cable

       

          Dell laptop USB A port – 5.08V  0.50A

          ThinkPad USB A port – 5.09V  0.48A

          ThinkPad USB A SS port – 4.85V  1.15A

       

      Adapters with only 5V Output using Type-A to Type-C cable

       

          Apple 12W USB power adapter – 4.92V  1.61A

          Samsung 5V 2A USB power adapter – 5.33V  1.76A

          Saltillo 15W USB power adapter (no resistors on D+/D-) – 5.11V  0.44A

          Saltillo 15W USB power adapter (75K/25K resistors on D+/D-) – 5.01V  1.62A

       

      Adapters with Adaptive Power

       

          Samsung 5V 2A, 9V, 1.67A Adaptive USB power adapter – 8.91V  1.60A

          ANKER 30W USB-C PD – 9.0V  1.4A

          KunX PD/QC 30W adapter – 9.0V  1.6A

         

       

      Thanks,

      Scott

        • 1. Re: BCR (CYPD-3177) and USB Type-A charging ports
          YiZ_31

          Hi,

           

          I don't have all these device but they should follow the Spec of Type-C.  Please check USB Type-C Specification 4.5.3.2.2.

          In this situation, all the proceduce follows Type-C spec not Power Delivery Spec, so the PDO set by resistor won't work. Fault will not be triggered.

           

          All the power adaper should have at least one vSafe5V PDO. That is the request of PD spec.

          BCR has two default PDO:

           

          PDO #1: Fixed Supply, 5V, 900mA, Higher_Capability = Yes if VBUS_MAX > 5V else No

          PDO #2: Variable Supply, Minimum Voltage = VBUS_MIN, Maximum_Voltage = VBUS_MAX, Operational Current = ISNK_COARSE + ISNK_FINE

           

          If your power adapter do not have PDO that can support 5V/2A, the fault LED will be on. Based on the maximum power of your adapter, I think they can all supply 5V/2A. So I guess they will not trigger fault LED. If your power adapter can only supply 5V/1.5A, the fault LED will be on.

           

          Regards,
          Eddie

          • 2. Re: BCR (CYPD-3177) and USB Type-A charging ports
            ScottK_91

            Thanks, Eddie.

             

            It's not clear how the BCR will function when it see voltage/current from legacy chargers using a Type-A to Type-C cable.

             

            Example:  If the BCR output is set at 5V and 1.5A, and it is connected to a legacy charger or laptop that supports 5V at 1A, what is present on the BCR output?

            • 3. Re: BCR (CYPD-3177) and USB Type-A charging ports
              YiZ_31

              Hi,

              Sorry for late reply.

              A standard USB port would only have 5V/0.9A 5V/1.5A or 5V/3A.

              If connected to a legacy charger, BCR will open VBUS gate due to no PD communication. It's behaviour is based on Type-C mechanism.

               

              Regards,
              Eddie

               

               

              Hi