Analysis of an oscillator consisting of digital integrated circuits

The authors present the theoretical and experimental investigations of an oscillator consisting of digital integrated circuits that act as nonlinear active elements. The circuit equation for this oscillator is derived from the inverse tangent approximation to the input-output characteristic of the digital IC. Using the perturbation method, the approximate solutions of this equation are obtained. The propriety of the inverse tangent approximation is ascertained by comparing the calculated and experimental value of the limit cycles.