An improvement on the analytical methods for amplitude analysis of the MOS Colpitts oscillator

Abstract

New analytical equations are proposed for oscillation amplitude of the MOS Colpitts oscillator. These equations are obtained from a large signal analysis. The analysis is based on a reasonable estimation for the output waveform. The estimated waveform should satisfy the nonlinear differential equations governing the circuit. The validity of the resulted equations is verified through simulations using TSMC 0.18 µm CMOS process. Simulation results show the accuracy of the proposed method for a wide range of circuit parameters.