I'm using a P-channel MOSFET Q57 as a switch for current from VIN_ALW_GATED to +VIN_ALW when VIN_ALW_GATED > 17.259 V.
In case VIN_ALW_GATED was not connected to any reference voltage (floating), and we connect another voltage source to +VIN_ALW, how I can prevent back current to go from the drain of Q57 to the source through the drain-bulk diode? Is this scenario possible?
I'm confused between connecting VIN_ALW_GATE (Gate of Q57) to GND or keep it floating, because, in case VIN_ALW_GATE was connected to GND, and assuming there was leakage current through this bulk-drain diode, it will go to the board GND. I'm trying to compare this with the gate left floating, in which I think there will no be such problem. Is my analysis right?