RC Phase Shift Oscillator Using an Op-Amp

Introduction Oscillators are fundamental building blocks in electronics, used to generate periodic waveforms without requiring an external input signal. One of the simplest ways to generate a sine wave is by using an RC phase shift oscillator. In this project, we’ll build an RC phase shift oscillator using an operational amplifier (op-amp). This design is widely used because it is easy to construct, stable, and produces a clean sine wave output. What Is an RC Phase Shift Oscillator? An RC phase shift oscillator produces a sine wave by combining an amplifier with a feedback network made of resistors and capacitors. The key idea is simple: The amplifier provides gain The RC network provides a phase shift To sustain oscillations, the circuit must satisfy the Barkhausen criterion , which requires: Total phase shift of 360° (or 0° effectively) Loop gain equal to 1 In this design: The op-amp provides 180° phase shift (inverting configuration) Three RC sections provide the remaining 180° Comp