internal pull up on 5 volt pin

trevor1 · ‎2009-10-05

Posted on October 05, 2009 at 16:18

trevor1 · ‎2011-05-17

Posted on May 17, 2011 at 13:25

Hi all,

Is it OK to enable internal pull up on port pin that could be exposed to 5 volts? The pin is a five volt tolerant pin.

I presume the internal pull resistor is connected to VDD (3v3 in my case) therefore there would be a small current flowing from the port pin (5V) through the internal pull up to 3v3.

It works but I was just wondering if it might damage the processor in time.

Regards

Trevor

tomas23 · ‎2011-05-17

Posted on May 17, 2011 at 13:25

I'd stick to maximum ratings in the datasheet: max. current in/out, max. voltage. There is most probably no danger.