Source Follower Large Signal - MOSFET amplifier

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The discussion centers on analyzing a source follower MOSFET amplifier circuit, with the user expressing confusion about the equations involved. Key equations mentioned include the output voltage (v_o) in relation to input voltage (v_IN) and threshold voltage (v_T), as well as the drain current (i_d) equation. It is pointed out that equations 3 and 4 are incorrect, emphasizing that v_o and v_S represent the same voltage. The user is advised to focus on equation 2 for clarity, but it is noted that the correct output voltage (v_o) is not known for the specific circuit in question. The conversation highlights the complexities of circuit analysis and the need for accurate understanding of the relationships between the variables.
krtica
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t50yew.png


I'm still not very confident in analyzing circuits. Here's what I know:

1) v_o=v_IN - v_T
2) id=k/2*(v_IN-v_T)^2
3) v_o=v_S-(k/2)(v_IN-v_T)^2*RS
4) v_o = v_S-id*Rs

iDS = v_o/RS
The answer I chose in the photo was based off of other online discussions. I'm very confused and don't have the slightest idea as to where to go. Any ideas appreciated.
 
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krtica said:
t50yew.png


I'm still not very confident in analyzing circuits. Here's what I know:

1) v_o=v_IN - v_T
2) id=k/2*(v_IN-v_T)^2
3) v_o=v_S-(k/2)(v_IN-v_T)^2*RS
4) v_o = v_S-id*Rs

iDS = v_o/RS



The answer I chose in the photo was based off of other online discussions. I'm very confused and don't have the slightest idea as to where to go. Any ideas appreciated.

Equations 3 and 4 are wrong. Note that Vo and Vs are the same voltage!

I would look carefully at eq. 2 ...
 
krtica said:
t50yew.png


I'm still not very confident in analyzing circuits. Here's what I know:

1) v_o=v_IN - v_T
2) id=k/2*(v_IN-v_T)^2
3) v_o=v_S-(k/2)(v_IN-v_T)^2*RS
4) v_o = v_S-id*Rs

iDS = v_o/RS



The answer I chose in the photo was based off of other online discussions. I'm very confused and don't have the slightest idea as to where to go. Any ideas appreciated.

Oh, BTW your answer is correct also. But for the given circuit, you don't know Vo.
 

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