If a GPIO has a max rated current of 40mA... what exactly happens if it is exceeded? By a little? By a lot?
I understand that it gets "damaged", but how? I figure it is one of the 3 options below:
1) The pin "breaks" and is stuck high, sort of like a shunt, allowing the current to flow (eventually causing a fire, which is manageable)
2) The pin "burns out" and is high Z (physically disconnected) - something like a fuse
3) The pin is in an indeterminate state... could be high, could be low, etc
Anyone know which? Is it consistent and predictable? I just hope someone's experience can give me a preview of what to expect.
The application calls for 3.3V micro powered by a 1S LiPo doing some job (not important what) and IF a certain terminal condition occurs, to briefly power a special bulb which will momentarily draw roughly 2A before burning out. At that point, it is perfectly OK for the device to be damaged... which is why I'm hoping it is #1 above and just becomes a shunt. If it is #2, then how quickly? Can I expect a few milliseconds of high draw to get through? A few hundred milliseconds?
If the answer is #2, then I need to handle the current more "normally"... a MOSFET switch. That's not so easy because I haven't found a MOSFET that can be switched at 3.3V and handle 2A/8W and is reasonably price AND is available :). Relay is just too big or expensive.