EASA / CAR Part-66 · Module 4 · 4.1.3 Integrated Circuits · Cat B1/B2

Operational Amplifier (Inverting)

An inverting amplifier's gain is set by two resistors: A_v = −R_f ÷ R_in. The output is a bigger, upside-down copy of the input, until it clips at the supply rails.

Input Rin 10 kΩ

Feedback Rf 100 kΩ

Input amplitude 1.0 V

Gain (−Rf/Rin)

Ideal output

Rails

±12 V

State

Blue is the input, green is the output. The gain magnitude is R_f ÷ R_in and the output is inverted (180° out of phase). If the demanded output exceeds the ±12 V supply rails, the peaks flatten, the amplifier clips (saturates).