- #1
Jalo
- 120
- 0
Homework Statement
Given the following circuit find the input resistance as seen through vo.
Homework Equations
The Attempt at a Solution
To solve this problem I started by drawing the signal equivalent circuit:
As we can see the voltage vgs = vi - vo. To find the input resistance I used Thenevin's theorem, placing a DC test voltage, VT, between the output terminals. By finding the relationship between VT and the current that passes throught it I hoped to find the value of the input resistance.
This, however, didn't take me to the correct result. I was told the result was equal to 1/gm || ro || Rs. I do not understand how to get to this result tho.. If someone could point me in the right direction I'd appreciate!