diode connected mosfet

[sinan2]

hello
if i connect the gate to drain in pmos mosfet
current goes from drain to source or from source to drain !!!!!!
because when i simulate sometimes it depent on the type of pmos
note : i need to pmos to have passive voltage doubler
thanks

 

[BigBoss]

Since the Source is more positive, the current will always flow from Source to Drain in according to "convention".
In fact MOS transistor structure is physically symmetrical so no matter what you call it as drain or source except particular MOS structures.

 

[crutschow]

A MOSFET cannot be made to act as a passive diode (other than by using the substrate diode) in a passive voltage doubler circuit.
It needs active control of Vgs to do that.
You need to do a different circuit.