High-frequency design of sinusoidal oscillators realised with operational amplifiers

The use of slew-rate models for designing RC active oscillators is discussed. It is shown that a precise modelling of the oscillator behaviour is obtained for frequencies beyond the ordinary application range of operational amplifiers. Based on that model, a design procedure is developed, and it is applied in the paper to the design of Wien-bridge oscillators, giving theoretical as well as practical results. Low-distortion oscillations may be obtained up to 100 kHz using standard operational amplifiers.