For a project I have to use a voltage level shifter. On both sides of this shifter I have to specify the target voltage. Thus my idea was to simply set one pin on high (3.3 V) and use that as VCC on one side. My question now is if that is sufficient, or if the Pi does not produce enough power for powering the shifter. Could I damage the Pi with that configuration?

2 Answers 2


I assume you are using a MOSFET Level Converter. You won't damage the Pi as the reference draws little current, but it won't work properly as the high level will be <3.3V. Why not use the 3.3V?

  • I need the reference for converting 5V input to 3.3 V input. What do you mean with "Why not use the 3.3V"?
    – arc_lupus
    Oct 20, 2014 at 12:10
  • I assume you are using a level converter to connect to Pi GPIO. The normal procedure is to use the Pi 3.3V supply (pin 1) as reference. This, after all, is the point of a level converter - to match the voltage levels on each side.
    – Milliways
    Oct 20, 2014 at 12:13
  • But it won't drain too much power? That was my original problem.
    – arc_lupus
    Oct 20, 2014 at 12:17
  • Any current you dray from the GPIO comes from the 3.3V supply, whether direct or via a GPIO pin.
    – Milliways
    Oct 20, 2014 at 12:23
  • Ok, that was something I did not consider (and it solves my problem). Thanks!
    – arc_lupus
    Oct 20, 2014 at 12:32

It depends on the amount of current that draws what you connect the pin to. I would not go far beyond 30mA

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