About Op-Amp Gain Calculator

This calculator helps you determine the gain of an operational amplifier (op-amp) based on the resistor values in either a non-inverting or inverting configuration. The gain is a crucial parameter in amplifier circuits, defining how much the input signal is amplified or attenuated.

Op-amps are widely used in signal processing and control systems, making accurate gain calculations essential for circuit design and analysis.

Mathematical Formula

1. Non-Inverting Amplifier

For a non-inverting amplifier, the gain is calculated as:

\[ Gain = 1 + \frac{R_2}{R_1} \]

• \( R_1 \): Resistor connected to ground (in ohms, Ω)
• \( R_2 \): Feedback resistor connected between output and inverting input (in ohms, Ω)

2. Inverting Amplifier

For an inverting amplifier, the gain is calculated as:

\[ Gain = -\frac{R_2}{R_1} \]

• \( R_1 \): Resistor connected to the inverting input and signal source (in ohms, Ω)
• \( R_2 \): Feedback resistor connected between output and inverting input (in ohms, Ω)

In this configuration, the negative sign indicates a phase inversion of the output signal.

Example Calculations

Non-Inverting Amplifier

If \( R_1 = 1kΩ \) and \( R_2 = 4kΩ \):

\[ Gain = 1 + \frac{R_2}{R_1} = 1 + \frac{4000}{1000} = 1 + 4 = 5 \]

The output signal is amplified by a factor of 5.

Inverting Amplifier

If \( R_1 = 1kΩ \) and \( R_2 = 4kΩ \):

\[ Gain = -\frac{R_2}{R_1} = -\frac{4000}{1000} = -4 \]

The output signal is inverted and amplified by a factor of 4.