3 Replies Latest reply on May 22, 2020 3:38 AM by LePo_1062026

    GPIO Pin as Power Pin

    gali_925661

      I have a small peripheral device which uses about 10mA current at 3.3V. I would like to know if it is possible to power it up reliably using PSOC6 GPIO?

      Thanks.

       

      Regards,

      Gary

        • 1. Re: GPIO Pin as Power Pin
          LePo_1062026

          Gary,

           

          Theoretically yes.   In theory, a PSoC6 GPIO is effectively limited to 8mA source current.  If you need to supply 10mA, I suggest you use at least two (preferably three) GPIO pins switched simultaneously to source >10mA.

           

          Due to possible noise influence on the ADC and/or CapSense internal circuits, I recommend that these peripheral supply pins be switched when the ADC or Capsense is not needed or ignore the readings from these resources when you do switch.

           

          Len

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          • 2. Re: GPIO Pin as Power Pin
            gali_925661

            Thanks. Will give it a try!

            • 3. Re: GPIO Pin as Power Pin
              LePo_1062026

              Gary,

               

              Are you willing to share which peripheral device you're using and the circuit connecting it?

               

              The reason I ask is that sometimes controlling the power to the peripheral can get a little trickier than first thought.

               

              For example,  let's say you cut the power (VDD) to the peripheral but your comm signals from the PSoC use pull-ups (such as the SDA line for I2C).  This pull-up could parasitically power your peripheral causing potential damage and at a minimum extra sleep current.

               

              This is why many SPI and I2C comm peripherals have a hibernation mode.  In this mode VDD is always applied but some signal (a serial command or a GPIO line) is used to place the device into hibernation.

               

              Len