I just started learning about Op-Amps. Working through basic equations seems straightforward, however I was curious about the function of the feedback resistor. As the name implies, one might infer the current/voltage potential "feeds back" from the output back into the input (I know there are two voltage potentials at each end of the resistor, Vo and the potential from the input pin). However, when the equations are defined (nodal analysis), the current is defined as moving through the feedback resistor towards the output pin. If you take a basic setup, the first resistor (say R1) is in series with Rf (assuming Ideal op-amp, hence no current flows into the inputs due to Rin = infinity), basically forming a voltage divider. In an ideal op amp, the closed loop voltage gain (inverting) is basically the ratio of Rf/R1 = Vo/Vin.(adsbygoogle = window.adsbygoogle || []).push({});

I guess I am looking for a simple English explanation, instead of the mathematical relationship, regarding the effect the feedback resistor imparts on the op-amp circuit, relative to input and/or output.

Thanks. Let the schooling begin ;)

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# Basic Op-Amp Inquiry - Rf

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