MOSFET PURPOSE

[irfan karatela]

I'm looking at the PS5 motherboard, and have come across 2 mosfets, I want to understand the purpose of the 2nd mosfet as the source is connected to GND and the drain is connected to 5v. wouldn't this short the 5v rail once the 2nd mosfets gate is enabled?

Thanks

[harp]

Maybe some type of switching power supply... I see coil on the right...

[truclacicr]

The ground-connected MOSFET is used as a freewheeling diode in a stepdown DC-DC converter. The other MOSFET is the chopper for the positive supply.