# How many mA are drawn per pin for logic actions on in and outputs?

I'm trying to figure out whay kind of battery I need for my project, and therefore need to calculate mAh.

In my project I'm using pins on the Arduino to tell mosfets when to switch to open and closed states. How many milliamps would be drawn by one of these pins to perform that kind of function? (Or, how can I go about finding out myself?)

Thanks!

In my project I'm using pins on the Arduino to tell mosfets when to switch to open and closed states. How many milliamps would be drawn by one of these pins to perform that kind of function

As mosfets have a very high input impedance the answer to the question is "sod all".

If the pin is being PWMed then you are constantly charging and discharging the gate capacitance so it is good to limit the peak current with a 150R series resistor. But the extra current although slightly bigger is still in the "sod all category".

Wonderful. Thanks for your response; this really helps!