1. What is the Inverting Op-Amp Gain Equation?

The inverting operational amplifier configuration provides a closed-loop voltage gain determined by the ratio of feedback resistor to input resistor. The negative sign indicates signal inversion at the output.

2. How Does the Calculator Work?

The calculator uses the inverting op-amp gain equation:

Where:

• \( R_f \) — Feedback resistor (Ω)
• \( R_in \) — Input resistor (Ω)
• \( Gain \) — Closed-loop voltage gain (dimensionless)

Explanation: The gain is determined solely by the external resistor ratio, making the circuit performance predictable and stable. The negative sign indicates 180° phase shift between input and output.

3. Importance of Gain Calculation

Details: Accurate gain calculation is essential for designing amplifier circuits, signal conditioning systems, and ensuring proper signal levels in electronic systems.

4. Using the Calculator

Tips: Enter resistor values in ohms (Ω). Both values must be positive and non-zero. The calculator will compute the voltage gain ratio.

5. Frequently Asked Questions (FAQ)

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

Q2: What are typical resistor values used?
A: Common values range from 1kΩ to 1MΩ. The ratio determines gain, so values can be scaled while maintaining the same gain.

Q3: Are there limitations to this equation?
A: This assumes ideal op-amp conditions (infinite input impedance, zero output impedance, infinite gain). Real op-amps have limitations at high frequencies and with very high gain settings.

Q4: Can I use this for AC signals?
A: Yes, the gain calculation applies to both DC and AC signals within the op-amp's bandwidth limitations.

Q5: What about non-inverting configuration?
A: For non-inverting op-amps, the gain formula is \( Gain = 1 + \frac{R_f}{R_{in}} \) and the output is in-phase with the input.