# Mosfet switching

I'm implementing mosfet switching circuitry using the P channel enchancement mode mosfet DMP2305U.Where Vs = 3V and Vg is using as control voltage and toggleing between 0 and 3V . When Vg is zero volts , I'm getting output at Vd as high , when Vg is 3Volts I'm getting output at Vd as low as desired functionality, but i'm not getting the sufficient current through the mosfet . It seems like Vth of this mosfet is -0.9V and as a ground rule , Vgs should be greater than Vth to supply the max current , but here in my case Vgs is -3V (When the mosfet is on Vg=0v and Vs=3) .Here, do we need to consider the signs ?(negative , positive) of Vgs and Vth ?

simulate this circuit – Schematic created using CircuitLab

• Drain current is dependent on load. What load do you have on the drain to 0 volts? Note that R1 is not connected in the right place to act as a load. Dec 12 '18 at 10:24

For a p-channel MOSFET like this one, $$\V_{gs}\$$ should be less than $$\V_{th}\$$ to enter triode or saturation operation, not greater than $$\V_{th}\$$.
Yes, you need $$\V_{gs} < V_{th}\$$ to form a channel, and $$\V_{th}\$$ will be less than 0 for an enhancement mode p-channel MOSFET.