https://easyeda.com/suntop/featherwing-isolated-fet-gate-drive

To enable this wing, a digital high is applied to pin 13 of mcu, which will enable the ap3012ktr DC-DC converter to power up and get the wing ready to operate.

Then enabling pwm to pin 12 of the mcu from code, the MOSFET can be driven.

It only requires 2 pins of Feather boards, rest of the pins can be brought up with long male/female pin headers !

Working Principle :

B1212S-1WR2 has a tiny flyback converter consists of switching element, tiny transformer and rectifier, which turns 12 volts into isolated 12 volts. This kind of isolation is galvanic isolation.

Flyback Isolated DC-DC converter (source: Wikipedia)

This isolated 12 volts is supplied to power the FOD3182 opto isolated gate drive IC. Inside this IC, there is an IR LED which can be turned on/off directly from 3.3 volts mcu GPIO pin through a current limiting resistor. The IR light will turn on or off the pull-push output drive transistors which will connect the gate drive pin to Isolated 12 Volts or Isolated Ground.

                                                     Fig: FOD3182 guts