2 Replies Latest reply on Oct 19, 2018 8:50 AM by lcamacho_2461841

    When the CYUSB3014 is configured for bus power mode, does it supply power to the logic core (VDD) internally by stepping down the 5V USB bus power with built-in regulators?

    lcamacho_2461841

      Hello,

       

      I have an application using the FX3 chip CYUSB3014 and I have a question about the logic core power:

       

      The VDD pins of the FX3 receive 1.2V from an external supply to power its logic core.  However, if the FX3 is configured (via firmware) to work on bus power mode instead of external power mode, does the FX3 provides power to the logic core (VDD ) internally (by stepping down the 5V USB bus power with built-in regulators)?

       

      The reason I ask is because I probed the 1.2V rail that supplies power to the FX3's VDD pins on my application and I read 0 Amps.  So, I guess that if the FX3 is not taking power from the 1.2V external power supply, it may be getting it internally from the 5V input on the USB bus, which is directly connected to the FX3.

       

      Thanks!