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Inverting Amplifier Gain Formula:
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An inverting amplifier is an operational amplifier circuit configuration that produces an output signal that is 180 degrees out of phase with the input signal. The gain is determined by the ratio of feedback resistor to input resistor.
The calculator uses the inverting amplifier gain formula:
Where:
Explanation: The negative sign indicates phase inversion. The gain magnitude is simply the ratio of feedback resistance to input resistance.
Details: Accurate gain calculation is crucial for designing amplifier circuits, signal processing applications, audio equipment, and instrumentation systems where precise signal amplification is required.
Tips: Enter feedback resistor and input resistor values in ohms (Ω). Both values must be positive and non-zero. The calculator will compute the voltage gain with proper sign for phase inversion.
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, which is characteristic of inverting amplifier configurations.
Q2: What are typical resistor values used?
A: Common values range from 1kΩ to 1MΩ. The ratio determines gain, so choose values that provide desired gain while considering op-amp limitations and circuit requirements.
Q3: Can I get gains less than 1?
A: Yes, if R_f is smaller than R_in, the gain magnitude will be less than 1, creating an attenuator circuit with phase inversion.
Q4: What are the limitations of this configuration?
A: Input impedance is relatively low (equal to R_in), and the circuit may require additional components for stability in high-frequency applications.
Q5: How does this differ from non-inverting amplifiers?
A: Non-inverting amplifiers have positive gain, higher input impedance, and the input signal is applied to the non-inverting terminal instead of the inverting terminal.