Diode Connected NMOS

Thread Starter


Joined Oct 18, 2011
The problem given states:

Two diode connected NMOS transistors are connected in series.
Calculate the current in the these devices if the voltage across the
series connection is 5 V. Both substrate contacts are tied to ground.

Device parameters: VTN = 0.75 V, mun*Cox = 2.5x10^1 uA/V2,
W/L = 10/1, gamma = 0.5 V0.5.

There are two things I am concerned with. After doing some searching I believe I have figured out what they are asking by two "diode connected NMOS". I want to make sure that the way I have drawn the schematic is the proper orientation of the circuit.

secondly I read that the current through one of the NMOS
I = .5*kn'(W/L)*(v-Vt)^2

The problem states that 5V is across the series connection so is that Vo between the two fets or is that Vcc to ground? For some reason I am having a tough time with this problem. I feel that it is simpler than I am making it I just would appreciate some help onto the right track.



Joined Nov 4, 2011
I dont know the details about the configuration but your substrates are not connected to ground. They are shorted to source.