noise comparions between Schottky and MOSFET
Reverse voltage protection, so then I assume (you show no schematic!) that you want a diode in series with your supply.

What makes you think that noise on the supply caused by the diode is an issue? Only in few scenarios I can imagine that to be a problem and then I would simply use decoupling capacitors after the diode to short any remaining noise to ground.

A circuit with a PMOS can also work but in general you will need to pay attention to the fact that all MOSFETs have a build-in Drain-Source diode and you do not want that diode conducting the inversed supply voltage. Look for examples how to do this.

As a MOSFET can have a very low Rdson when used properly, it will not add much noise but again, noise should not be an issue and if it is, use supply decoupling.

If you do not use supply decoupling then the variations on the supply voltage caused by the circuits operating will very likely cause more noise than the diode!

If you're desperate about your supply (noise) consider this circuit:







simulate this circuit &ndash; Schematic created using CircuitLab

Here if you reverse power it, the fuse will blow.

You can also use a (self recovering) poly fuse.

You can use almost any diode as it just needs to conduct when power is reversed.

The diode is in reverse mode, no current flows in normal operation.

It is still a good idea to add a supply decoupling capacitor.