Inverting Op-Amp Amplifier

How to Use

• Adjust Rf (feedback resistor) and Rin (input resistor) to change the gain
• The gain is displayed as \(\text{Gain} = -R_f / R_{in}\)
• Adjust Vin amplitude and frequency to see the waveform scale
• The red dot at the inverting input shows the virtual ground (V ≈ 0)

What to Observe

• Phase inversion: output (red) is always 180° out of phase with input (blue)
• Gain magnitude: increasing Rf or decreasing Rin makes the output larger
• Virtual ground: the inverting input stays near 0V due to negative feedback
• Gain > 1 means the output amplitude exceeds the input; gain < 1 is attenuation