Pick your Op-Amp Configuration, enter your Input Resistor (R1) and Feedback Resistor (R2) values (with units), and optionally add an Input Amplitude to get your circuit's Voltage Gain, Gain in dB, and the resulting Output Amplitude — all calculated from your resistor ratio.
Voltage Gain
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Gain (dB)
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Output Amplitude
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An operational amplifier (op-amp) is a high-gain electronic voltage amplifier with differential inputs. It's a fundamental building block in analog circuits used for signal amplification, filtering, and mathematical operations like addition, subtraction, and integration.
For an inverting op-amp, gain = -R2/R1 (negative due to phase inversion). For a non-inverting op-amp, gain = 1 + R2/R1. The gain depends only on the external resistor values, not the op-amp's internal characteristics in ideal conditions.
An ideal op-amp has infinite input impedance, zero output impedance, infinite gain, infinite bandwidth, and zero offset voltage. It draws no current from input terminals and responds instantaneously to input changes.
Op-amps are used in audio amplifiers, active filters, voltage followers, comparators, integrators, differentiators, instrumentation amplifiers, and signal conditioning circuits. They're essential in analog signal processing applications.
Inverting configuration produces an output that is 180° out of phase with the input, with gain = -R2/R1. Non-inverting configuration produces an in-phase output with gain = 1 + R2/R1, always greater than 1.
Op-amps are called differential amplifiers because they amplify the difference between two input signals (V+ and V-). The output is proportional to the voltage difference between the inverting and non-inverting inputs.
Thermal drift refers to changes in op-amp characteristics due to temperature variations. This includes offset voltage drift, bias current drift, and gain variations that can affect circuit accuracy in temperature-sensitive applications.