An inverting operational amplifier (op-amp) circuit is a common configuration where the input signal is applied through a resistor to the inverting (−) input, while the non-inverting (+) input is grounded. A feedback resistor connects the output back to the inverting input, creating negative feedback. This setup causes the output voltage to be 180° out of phase with the input (inverted). The voltage gain is set by the ratio of the feedback resistor to the input resistor (−Rf/Rin). Because of the virtual ground at the inverting input, this circuit provides precise, stable gain with predictable performance.
