SparkFun Forums

[jonbarril]

I have had trouble in the past driving arduinos from an external 12V supply, even though the devices were supposed to be rated at 12V. Has anyone actually tried the Pro Micro with a 12V supply? Is it happy? Does it overheat?

[Valen]

It depends on how much current your draw in your circuit. The heat comes from the excess voltage that needs to be dropped in the regulator times the current that you circuit needs to operate. Just running the pro micro on it's own from 12 volt should be no problem. That's a few 10s of milliamps. If the regulator also needs to feed a whole bunch of leds, motors/servos, heating element, whatever then the excess current draw is going to cause temperature rating problems.