1. What is Op Amp Gain?

The gain of an operational amplifier (op amp) circuit determines how much it amplifies the input signal. For an inverting amplifier configuration, the gain is determined by the ratio of feedback resistor (Rf) to input resistor (Rin).

2. How Does the Calculator Work?

The calculator uses the inverting op amp gain equation:

Where:

• \( R_f \) — Feedback resistor (ohm)
• \( R_{in} \) — Input resistor (ohm)

Explanation: The negative sign indicates the output signal is inverted relative to the input. The gain magnitude is simply the ratio of the two resistors.

3. Importance of Gain Calculation

Details: Proper gain calculation is essential for designing amplifier circuits with desired signal amplification characteristics in audio, instrumentation, and control systems.

4. Using the Calculator

Tips: Enter resistor values in ohms. Both values must be positive numbers. The calculator will compute the gain (dimensionless) which represents the amplification factor.

5. Frequently Asked Questions (FAQ)

Q1: Why is the gain negative?
A: The negative sign indicates the output signal is inverted (180° phase shift) relative to the input in this configuration.

Q2: What are typical resistor values used?
A: Common values range from 1kΩ to 1MΩ, depending on application and desired gain. Values too low may overload the source, while values too high may introduce noise.

Q3: Can this calculator be used for non-inverting configuration?
A: No, this calculates gain for inverting configuration only. Non-inverting configuration uses a different formula: \( Gain = 1 + \frac{R_f}{R_{in}} \).

Q4: What about frequency response?
A: This calculator provides DC/low-frequency gain. Actual gain may vary at higher frequencies due to op amp bandwidth limitations.

Q5: How does input impedance affect the circuit?
A: For an inverting amplifier, the input impedance is approximately equal to Rin, which should be considered when designing the circuit.