PMOS Working Concept: Vgs (th) -5V Source Follower Mode Output

[hemant03]

Hi,
I believe that to make a PMOS work, Vgs (th) needs to be negative but when I give -5V to source and connect it in a source follower mode i.e. vg = -5V, I do get an output.
Can anyone tell me how and why?

Thanks,
- Hemant

 

[uart]

1. Can you post a circuit diagram.

2. Can you make it clear whether you are using mosfets or jfets.

 

[hemant03]

1. Can you post a circuit diagram.

2. Can you make it clear whether you are using mosfets or jfets.

Hi,
I have attached a sample PMOS circuitry that I have simulated. I am actually using a PMOS FET.

 

[Corneo]

Thats because you shorted the gate and the source together. They are tied to -5 Volts with respect to ground but not -5 volts with respect to source.