I can't understand how MOSFET LDO works and when it would be low drop.
Below, there is a simple schematic with N channel mosfet and TL431. Providing gate voltage, D-S will open, but minimum Gate-Source voltage for eg. IRF540 is 4V (for 1A drain current). Load is connected between source and GND, so minimum Gate-GND voltage is Vout+Vgs=Vout+4V, so whole Vin is minimum Vout+4V.
Do I understand it correctly?