Drain current of Depletion type MOSFET in two different regions

Thread Starter

Babun Pal

Joined Jul 13, 2016

I have a few doubts about depletion type MOSFET:

1. The schematic symbol of Depletion type MOSFET and Deletion-Enhancement type MOSFET are the same. Therefore, if any one of them is used in a circuit schematic, how can we distinguish them?

2. For Enhancement type MOSFET, the drain current in two different regions are:

Triode region:


Saturation Region:


What are the drain current equations for a Depletion type MOSFET in saturation region and triode region?

Would you be kind to clarify me the above two doubts?

Thank you.


Joined Mar 14, 2008
You would have to look at the part number to determine whether the MOSFET is enhancement or depletion.

I believe the equations are the same except Vth is opposite polarity for a depletion mode.