4 Replies Latest reply on Mar 19, 2020 12:16 AM by NoAr_1540581

    About VCONN supply under 1w.




      After confirming the VCONN request, in case of 3A or more, VCONN needs 1W capacity to supply power to e-Maker.


      Q1) When connecting a cable with eMaker at 3A or less, is it correct to understand that PD charging is not possible without the capacity of 1W?

      Q2)  In this Q1) case, is it correct to understand that the cable with eMaker can be used by supplying power with an external LDO?



      Best Regards,


        • 1. Re: About VCONN supply under 1w.

          VCONN is provided by the Source to power cables with electronics in the plug.  VCONN is provided over the CC pin that is determined not to be connected to the CC wire of the cable.


          Initially, VCONN shall be sourced on all Source USB Type-C receptacles that utilize the SSTX and SSRX pins during specific connection states.

          Subsequently, VCONN may be removed under some circumstances.


          VCONN may also be sourced by USB Type-C receptacles that do not utilize the SSTX and SSRX pins. USB PD VCONN_Swap command also provides the Source a means to request that the attached Sink source VCONN.


          For more information, please check "4.4.3  VCONN" in USB Type-C Spec.

          As per "Table 4-4  USB Type-C Source Port’s VCONN Requirements Summary" in Type-C Spec, the voltage is 3A or less, VCONN is not required.


          In case CCGx is used for E-marker, if CCGx is set to "VCONN Required" on "Cable termination type" parameter, VCONN is keep supplied.

          Also, if the source device is CCG3 or later, VCONN can supply by enabling "Vconn Retain On". Attached Excel has described the detail.


          Please let me know if you need more information.


          Best regards,

          Hirotaka Takayama

          • 2. Re: About VCONN supply under 1w.






            Q1) VCONN要求を確認すると、3A以上の場合はeMakerに電源供給をするため、VCONNの容量が1W必要と記載されております。3A以下でeMaker付きケーブルを接続した場合、1Wの容量がなければ、PD充電できなくなるのでしょうか?

            Q2) Q1の内容でPD充電ができなくなる場合、その電力は供給可能なのでしょうか?




            上記Q1,Q2を考える上で、USB Type-C Cable and Connector SpecificationのPage144 Table4-5 Vconn Source CharacteristicsよりVCONN容量はMinimum 1Wと考えられます。

            上記Q1から、1Wの容量が無い場合のあくまで一例として、5V/x=0.9Wの時(A=0.18A)が下記USB PD spec rev.3の下記表の

            Current at 5V(A) の ”X ÷ 5"に当てはまると思います。



            更に、上記 5V/0.18A時は、1W未満なので、eMakerデバイスが機能しないと思いますが、3A以下ではもともとeMakerは不要なので、eMakerデバイス付きケーブルを、1W未満(5V/0.18A)で使用しても、eMakerとしては機能しないが、PDとして









            マクニカ 荒井

            • 3. Re: About VCONN supply under 1w.



              Hope you will continue to discuss in English because you started to speak English. All of the users who is seeing this thread may get confused if you suddenly start to speak Japanese. It is basic manners.


              As per the Type-C Spec, if SuperSpeed Signals or VPD support is required, 1W is a minumum.

              The detailed required Wattage has described in "Table 4-4  USB Type-C Source Port’s VCONN Requirements Summary".


              Anyway, As per you mentioned to me about "10.2.2  Normative Voltages and Currents", USB PD controller can negotiate minimum 0.5 Wattage (5V 0.1A). Therefore, the answer is that CCGx can do USB PD power supply.

              This can see if you use our Cypress Evaluation Kits such as CY4531 with E-marker installed cable (CY4505 is able to use for test).



              Hirotaka Takayama

              • 4. Re: About VCONN supply under 1w.



                Thank you for your reply.


                Best Regards,