Help with my first Power Distribution Board
New PCB designer here. This is my first Power Distribution Board for a project I'm working with... It is supposed to distribute power for an automotive project.
This is the schematic. It takes one input power from the source (stepped down externally or otherwise) as 3v3, 5v, 12v or 24v. The 24v rail also feeds to an external converter stepping down to 19v, hence a fifth rail. The whole system has to be capable of running upto 20A on each rail, and support upto 10A on individual rails. That was the requirement given to me.
The problem for me is the safety circuitry. I have used the P-channel MOSFET along with the zener diode to prevent issues when reverse polarity connection occurs on the input connector. Is that necessary?
And I have used decoupling capacitors on the input rail. I have put one decoupling cap on the J5 connector to show how I would replicate decoupling caps on other individual loads.
Apart from that, here's my previous attempt at designing the board BEFORE the caps and when i was using an IRF5305 instead:
Thank you for any help!!!