2 Replies Latest reply on Jun 20, 2018 8:41 AM by e.pratt_1639216

    Cy_Pin Current Leakage

    ayork_3398046

      I am looking into fine-tuning my power consumption. I have 7 Pins set up as digital outputs, and 2 set for Digital inputs in my project. An engineer I work with mentioned that there might be current leakage with the pins. I have no idea about this stuff, so I came here!

       

      Is there current leakage with the pins? If so, about how much, and how can I prevent the leakage? I understand that this would only save me a few nano amps, but I'm running a battery operated build, so anything I can save is worth the time.

       

      I have listed all of my pin configurations below. Please let me know if there is anything I can do to save current. Thanks!!

       

      ---------------------------------------------

       

      Red LED/ Blue LED

      Digital Output - Open drain, drives low - Initial Drive state = High (1)

       

      Green LED

      Digital Output - Open drain, drives low - Initial Drive state = Low (0)

       

      LED Driver / Audio_1 / Audio_2 / Audio_3

      Digital Output - Strong Drive - Initial Drive state = Low (0)

       

      Button_1 / Button_2

      Digital Input - High Impedance Digital - Initial Drive State = Low (0)

        • 1. Re: Cy_Pin Current Leakage
          Gyan Chand

          Hello,

           

              The GPIO's leakage current very much depends on your externally circuitry and its functionality. Based on the external circuitry operation , you can change the GPIO logic state either '0' or '1', when needed.

           

          When a particular GPIO is unused in a specific time interval , it is always recommended to select the GPIO drive mode as  Analog High -Impedance.

           

          Please refer page#9 ( GPIO Section) of below document for more details --

           

                      http://www.cypress.com/file/121271/download

           

           

          -Gyan

          • 2. Re: Cy_Pin Current Leakage
            e.pratt_1639216

            For example, if you have output RED LED connected to Ground of the battery, then when you drive it LOW, there will be no leakage current.

            If you have the RED LED output connected to the positive terminal of the battery, then when you drive it LOW, there will be a current leakage, as you are having a mismatch of voltages between the GPIO and the external battery supply.

            As gyan stated, if you set the pin output drive mode to Analog High-Impedance, it will behave close to "disconnected" for leakage and should have little-to-no current leakage. Otherwise, you will need to setup the output voltage level to match the voltage level the pin will see for least current leakage.