rsdio writes: More good ideas to steal and repurpose
This circuit maintains power to the load regardless of momentary shorts or opens in the supply voltage, and includes a low-current overvoltage-protection IC (MAX6495) that protects the load against transient voltages up to 72V.
Q1 & Q2 are opposite polarity, but have the same part number. Likewise for Q3 & Q4. Hmmm…
IRF7105 has one P-channel and one N-channel MOSFET in it, so actually Q1 is IC1-A, Q2 is IC1-B
Also Q3 and Q4 are mirror images.
Would this still require a Schottkey diode for reverse voltage protection?
I don’t think you necessarily need a Schottky for reverse-voltage protection – any diode should do. The Schottky has a low forward-voltage drop, but there are other LDO diodes out there.
If there is a chance that the input will have reverse polarity, then you should check the MAX6495 data sheet for voltage tolerance on the pin 1 input. Q1 and Q3 should handle negative voltages, but I can’t be sure without checking their data sheets, too.