Pin 2 and 7, and the PolyFuse of the Pro Micro and Type-C version

Development Boards Arduino
1

https://cdn.sparkfun.com/assets/4/4/f/2 … ematic.pdf

Pin 2 and 7 of the ATmega32U4 are not protected by the polyfuse.

what’s the reason behind this?

2

Hi there.

The polyfuse is there to protect the voltage regulator from an overcurrent condition rather than the ATmega. If pins 2 and 7 are drawing excess current, the ATmega32U4 is already dead.