Analysis of a Digitally Controlled Wien-Bridge Oscillator

Abstract: Of all the low-frequency oscillator configurations, the Wien bridge is the easiest to use. It is reliable, uses standard components, gives a good sine wave, and is fairly immune to the type of op amp around which it is designed. A Wien bridge can, however, be misunderstood and oversimplified, leading to designer frustration. This article describes the theory and practicalities of using a Wien-bridge oscillator, and how to make the circuit more stable and more factory-/user-flexible.