I have a arduino set below:


Now, I am expecting 1.2mA current flow through the pin that is set as output. Is that accepted? If so, what it the max current a pin can sink?

The current comes from a pul up resistor on the line

note: I can't protect it with a diode.

  • Arduino pin current limitations Commented Nov 8, 2017 at 22:07
  • wouldn't INPUT allow more current?
    – dandavis
    Commented Nov 9, 2017 at 7:00
  • yes it would, but Really what I'm doing in toggling between input and output LOW. The goal is to toggle the node from 0V to 3.3V.
    – Ryan B.
    Commented Nov 11, 2017 at 16:08

3 Answers 3


Ok, I just found it.

from the arduno docs:

Atmega pins set aa output can source (provide positive current) or sink (provide negative current) up to 40 mA (milliamps) of current to other devices/circuits.

  • 6
    That's the absolute maximum rating. Recommended is 20mA Commented Nov 8, 2017 at 22:11

Yes it can. This blog post of mine will help to explain it.

In short:

It’s all so simple now, isn’t it? The output pin is just like a switch that either connects it to 5V or to ground.


can arduino on output mode sink current?


from the arduno docs:

the datasheet for the particular device is the best place for that answer.

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