Engineering Differentiating Op Amp circuit help

AI Thread Summary
To find V0 in terms of R1, R2, R3, and C, KCL must be applied at the node between C and R1, considering R1 and R2 are in series. The node between C and R1 acts as a virtual ground, which simplifies the analysis. The initial equation provided is incorrect and needs to be revised to accurately reflect the circuit dynamics. Writing KVL for each node will clarify how to incorporate R3 into the calculations. Properly applying these principles will lead to the correct expression for V0.
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Homework Statement


(See attached figure) I need to find V0 in terms of R1, R2, R3 and C.

Homework Equations


V0 = -RC (dVs/dt) for a differentiator

The Attempt at a Solution


I understand I have to apply KCL at the node between C and R1, and I've also determined that R1 and R2 are in series (not sure) but I don't know what to do with R3.

{C * (d(Vn - Vs)/dt)} + {(Vn - V0)/(R1 + R2)}
 

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Hey Did u notice that the node between C and R1 is a virtual ground.
 
crixus said:
Hey Did u notice that the node between C and R1 is a virtual ground.

Plus you're missing one node, plus your equation is incorrect I'm afraid.

Just write the KVL for every node correctly & it'll be obvious what to do with R3 ...
 
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