11 Replies Latest reply on Nov 19, 2020 8:56 AM by SananyaM_56

    CY7C65642-48AXCT USB Hub & power switch implementation regarding




      I gone through the application note for power switch implementation.

      I noticed that the example image having active high enable power switch. So the PWR#[n] outputs are pull-up by 100K

      If i'm using active low enable power switch, i have to use pull-down resistor as per the application note statement.


      I have formulated the below table as per my understanding. I would like to the expected behavior for Case3 and Case4

      For example,

      if am using active low enable power switch and set the PWR#[n]=0. What will be the behavior of the downstream port.


      1. Is there any specific reason to use EN=1 power switch when PWR#[n]=0.
      2. Is it advisable to use EN#=0 power switch when PWR#[n]=0


      USB Hub PWR#[n] OutputPower switch Enable inputRemarks
      Case10 (default)1 (EN)Power switch with active HIGH enable input to be used
      Case21 (PWR_PIN_POL=1)0 (EN#)Power switch with active LOW enable input to be used
      Case30 (default)0 (EN#)
      Case41 (PWR_PIN_POL=1)1 (EN)



      Awaiting your response eagerly.



      Malathi T