1 Reply Latest reply on Aug 8, 2019 1:47 PM by SaBh_294166

    Confused about Provider and Consumer FET roles

    SaBh_294166

      Hi. Somewhat confused about the consumer & provider FET switches and their roles as applied in the Cypress PB ref designs.

       

      Reference:

      EZ-PD Type-C USB

       

      and

       

      CY4532 EVK

       

      1) On both the following blog design webpage & CY4532 EVK, the Southchip SC8802 buck-boost is used. This regulator is bidirectional where DIR decides the direction of the current flow.

       

      EZ-PD Type-C USB

       

      Based on this understanding, why is there a mosfet load switch for CONSUMER and yet another mosfet load switch for PROVIDER? Since even the other side of these switches mate with the common USB_TYPEC_VBUS pin.

       

      2) Also, in tracing the CY4532 EVK schematic, it appears that the CONSUMER & PROVIDER switches are shorted via R20 = 0 ohms (CY4532 Power Board).

       

      Perhaps the idea of a CONSUMER load switch & PROVIDER load switch are for other types of buck-boost regulators but cannot see the value if using SC8802 or similar. To clarify our understanding, the separate load switches are necessary if the destination pins are separate from each other? (ie. separate pin for the BATTERY_CHARGE and separate for the VADP?)

       

      In our specific case, we have a bidirectional buck-boost that is I2C driven - so at most, we require a single mosfet load switch for our DRP PD3.0 design?