I want to design a high side load switch which can allow or block DC current in either direction based on a 3.3V input.
The 3.3V rail is potentially created as a result of power being applied on either side of this switch, so with the thought that the 3.3V rail may still be coming up, the switch should be open (blocking) with it not present.
I would like to switch voltages up to 20VDC.
The circuit that I have currently looks like this:
This works with some caveats:
Some current passes through for about 10ms when power is applied. I'm not sure I completely understand why but I'd like to mitigate/remove that. For it to be that long, it would seem to not be related to the switching time of the MOSFETs, and swapping the 100k resistors for 1k didn't change it.
For switching 20V, I need to select P-FETs where Vgs can be 25V or greater, which limits my parts selection. This is not the end of the world but maybe there's a better way to do it.
How can I improve this circuit, use smaller/cheaper/fewer parts, and mitigate the caveats above?
This is ultimately part of a USB C power mux circuit as I mentioned in my previous question, so ideally I want to be able to have two of these and open one, or the other, or neither, but never both at the same time (because then 20V may end up on my VBUS rail and that's no good for anyone). This may be out of scope for this question but I provide this info to avoid the XY problem.