I have a question about PMOS load driver. When V1 is high then Vout should be 1.5 V and it is okay. But when V2 is high, Vout should be 3 V rather than 2.4 V.
Can anyone explain me why this 2.4 V
It's because of the body diode inside the M2 MOSFET: -
The 3 volts is fighting to push current through the body diode and can't win.
Can anyone explain me.... how can I fix this?
One option is to use back-to-back MOSFETs as per a solid state relay: -
Picture taken from this question. Back-to-back MOSFETs can handle bidirectional currents: -
Picture from here. Or use a proper power path controller like this chip that also uses bidirectional MOSFETs: -
Image from here.