Electronic Circuits Help Analyzing CS NMOS Amplifier

Thread Starter


Joined Oct 9, 2008
Hello all! This is my first question asked on here so hopefully I don't break any rules!

I just finished taking a quiz in my Electronic Circuits 1 class where we were given the circuit attached and were asked to find the following:

Gate voltage, Vg
Gate source voltage, Vgs
DC biasing drain current, Id
dc biasing drain-source voltage, Vds
small-signal input of the amplifier, Ri
small-signal transconductance, gm
small signal output resistance, ro
small signal no-load voltage gain, Avo
Small signal on-load voltage gain, Av

All we were given besides the circuit was that Vt = 2 V; k = 5 mA/V^2; and Vm = 100V.

Vt is the threshold voltage and Vm is the channel modulation voltage.

I was just wondering if someone could help me in where to start, or point me somewhere where I could see how to do this analysis.

For the actual quiz, there were some formulas in the book, but it said we needed to know the drain current Id, but it seemed to me that depended on the gate-source voltage Vgs, both of which were unknown. Because of this confusion I did not know where to start and thus did really bad on the quiz since almost everything depended on the Id and Vgs.

Any pointers or links to anything useful would be very much appreciated! Thanks in advance :D