I'm using this MCU board that is PoE-powered and it gets out 12V from pin 20. I'm also using an LM2596 in order to get those 12V and then power out 5V to power all board peripherals.
Also, I'm using the same LM2596 to manage the DC input (8-36V).
The issue is that I need that the MCU board will output 12V or will get the 12V from the DC side, because I need also the 3.3V that comes from MCU board.
At this time, I need a sort of switch mechanism that implements this logic:
- When DC Input is on, board will be powered from DC input (12V through pin 20 and the MCU 3.3 step-down converter will power up the 3.3V branches)
- When PoE is on, board will be powered from PoE and the 12V gets through pin 20
- When both PoE and DC input are there, it will be powered from the DC input.