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I understand that one of the input to the opamp is current , but what confuses me is that the other input is some voltage. I am trying to find the Voltage output, but the virtual earth theorem confuses me, because there are 2 different inputs.
Could anyone help me to find the Vout of the circuit, please?
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June 04, 2020 |
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I think the easiest way to think about this circuit is to remember two principles:
Because of #1, the current through R1 is equal to the current through I1. And because of #2, the op-amp will adjust its output so that the inverting input equals the virtual ground. I've copied and pasted your circuit here, and added node labels on the inverting and non-inverting inputs, and also set it up for DC Sweep simulation: If we let $I = \text{I(I1)} = \text{I(R1)}$, then from Ohm's Law we have: $$V_\text{out} - V_\text{inv} = I \cdot R_1$$ and from the ideal op-amp: $$V_\text{inv} = V_\text{virtual_ground}$$ so $$V_\text{out} = V_\text{virtual_ground} + I \cdot R_1$$ |
by mrobbins June 04, 2020 |
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