Design of an amplitude-stable sine-wave oscillator

Abstract

Two difficulties associated with the design of oscillators are to achieve amplitude and frequency stability. The latter problem is generally one of selecting the proper components, whereas the former dictates what basic type of oscillator should be designed. When amplitude stability and distortion are not critical considerations, a simple limiting type of oscillator is often adequate. One method of attaining amplitude stability is to incorporate an additional feedback loop, such as Automatic Gain Control (AGC) loop. This type of loop can be easily incorporated with the basic Wein-bridge oscillator. As will be shown by employing integrated circuits, such as the /spl mu/A709, an amplitude stability of /spl plusmn/0.50 percent over a temperature range of -50/spl deg/C to 100/spl deg/C can be achieved.