Switching USB-C power off to protect Arduino?

Other Hardware General Electronics
1

I have a bad habit of forgetting to unplug the USB on my Arduino when I turn the main power off for my system. Instead of the main 36V power supply powering the Arduino through the VIN (though a buck converter at 12V) and all the other components of my system, suddenly there is a huge power draw on the Arduino trying to make up for the missing 36V and powering everything. I don't think that this is very good for the Arduino.

I have been trying to find a USB-C to USB-C switch that essentially acts as a dead man's switch so that when the 36V power gets switched off, the USB power also gets disconnected so that it's not trying to power everything. I haven't been able to find any modules like this though.

So I am thinking about trying to build a switch using a P-channel MOSFET and an NPN transistor. Before I go building something like this though, I was wondering if anyone here knows of anything like this on the market, if anyone has advice about building a USB power cutoff switch, or whether something like this is even necessary with the Arduino Giga. Thanks!

2

You can Add a Schottky diode or ideal diode on your external 5V input
or use a USB isolator (best, but slower).
The USB-A por supplies power by design, the USB-C port should NOT backfeed, but small leakage is possible.

4

It is necessary.
This little board will do what you want but you will have to do some soldering and USB-C cable splicing.