I'm working on a project that operates at 5v – and can draw UP to 10 amps. Under normal conditions, it won't be doing that – probably closer to 3 amps, and (if configured for low-power) only 450mA or so.
It's designed to be powered from USB when in low-power mode, but I also want to have 2 barrel jack to add external power supplies (5V, 8A from aliexpress). Obviously I don't want the power supply backfeeding the USB, or the USB backfeeding the power supply. I want the option to plug in two of these power supplies because most of the time, I won't need to activate the 10A mode – so just one power supply would be sufficient.
Considering these power supplies are not designed to be paralleled (no master/slave setup, etc), how effective would an ideal diode be in enabling these various sources to all operate in parallel (to increase max current)?
Note that I don't need the load sharing to be perfect, but I'd like to avoid serious issues. I originally thought I could just use a P-Channel MOSFET, but after some research have learned that when they are "on" they allow current to flow both ways, which makes them non-ideal non-diodes (less than helpful).