Electrical

Inverting Op-Amp: Gain and Virtual Ground

Electrical Diagrams · made in Skemio

Circuit schematic ladder showing a dual supply reference driving an input resistor Rin, a feedback path with resistor Rf, and a DC voltmeter measuring output.
Circuit schematic ladder showing a dual supply reference driving an input resistor Rin, a feedback path with resistor Rf, and a DC voltmeter measuring output.
Open it in SkemioMake your own

What it shows

  • Gain is set precisely by ratio -Rf/Rin, independent of internal open-loop gain.
  • Inverting pin sits at a virtual ground (0V) because negative feedback drives it.
  • Input impedance equals Rin, so avoid small Rin to prevent loading your signal.

The takeaway

Negative feedback forces the summing junction to virtual ground, making closed-loop gain rely purely on two resistors.

More electrical diagrams