I was looking at this open-source power supply circuit for an automotive CANBus device. I am wondering it would include both a Schottky Diode (D1) and a MOSFET (Q1) on the power supply line. My understanding is that both of these are to provide reverse-voltage protection.
Is redundancy of two reverse-voltage devices just that, to have a failsafe? Or do these two devices have different characteristics that make it desirable to have both?
Edit: Here is a link to the schematic: https://github.com/macchina/m2-hardware/blob/master/M2/Interface%20Board/Interface%20Board%20Schematic.pdf
It is from the open-source Macchina M2 CAN Bus network analyzer.