How is the gain of a closed-loop op-amp circuit determined?

In a closed-loop operational amplifier (op-amp) circuit, the gain is primarily determined by the external feedback network, which consists of resistors or other components connected to the op-amp's output and input. This feedback network establishes a controlled response of the circuit by setting the ratio of the resistances in the feedback path. Specifically, the gain can be calculated using the formula based on the resistors used; for example, in a non-inverting configuration, the gain is given by 1 plus the ratio of the feedback resistor to the input resistor.

This feedback mechanism allows the gain to be fixed and stable, making closed-loop configurations valuable in precision applications where predictable performance is critical. The external elements effectively dictate how the op-amp processes the input signal, rather than solely relying on the internal properties of the op-amp itself or the input voltage.

While the power supply voltage does influence the maximum output swing of the op-amp, it does not directly determine the gain of the closed-loop circuit, making the external feedback network the essential factor in gain calculation.