Make a PMOS open drain circuit in LTSpice

[Saimoun]

Hi

Just a quick question: I know more or less how an open drain works - pullup resistor, and then a NMOS with it's source connected to ground.

I am trying to do the same with a P-MOS, basically a pulldown resistor and a PMOS connected to +5V. Kind of the upper part of an MCU push-pull output.

I tried in LTSpice and I cannot seem to get it to work? It seems changing the type of PMOS makes a difference but the output never goes to 0V or even near that.

See the attached schema.

Thank you

[fourtytwo42]

I am sure there was a similar question on here recently,
However, check your polarities, they are wrong AND
You say you want open drain but it is your source that is the output in that circuit

[Saimoun]

Ahhh ok that was dumb 

Yes it works better the right way