Pmosfet always turned on

[rajijames25]

Hi ,
I have a circuit with PChannel FET with Source is connected to 1.8V .I see that always the drain is high even when the gate is more than 5V . When i make the gate go low , the 1.8v signal will go down and come up .why so ?

 

[Ice-Tea]

Might help if you included the type of P-Channel you're using

 

[kabiru]

Try and connect 10k resistor from drain to ground and another 10k from gate to your vcc.

 

[dick_freebird]

You have a big gate charge that will kick the source and drain
if they are high impedance.

If your drain is higher than source, what is your body diode
up to?