Short circuit proof high side switching.

I need to switch 12V via a 5V signal (microprocessor). However, there is a chance that the output could become a short circuit and I'd like for it to not go pop. Can anyone suggest a circuit that would supply 12V at 350mA from a car battery that when shorted would limit the current to around 1A? I'm starting to think that a LDO regulator with an enable pin would be my simplest solution - any suggestions?

Mike.

Should work, with the reg wired as a current-limiter, if the enable pin accepts a logic-level input.

If you set the current limit at 1A you are going to have to dissipate 12W in the regulator. How long can you tolerate that much heat? You would have to sense the current and turn the switch off.

The TI LMP8646 may do what you want.


https://www.ti.com/product/lmp8646

Could you use foldback current limit, if the current gets to 1a instead of maintaining it at that knock it back to 100ma or so till the short is removed.

LT4363: this protects against a whole load of nasties that an automotive supply can throw at you. It also has a time that stops the pass FET overheating in the event of overstress:
https://www.linear.com/product/LT4363