A programmable switched-capacitor relaxation oscillator with low phase jitter

This paper describes a programmable low-jitter switched-capacitor (SC) square-wave oscillator for use in a variety of voice band signal processing applications. The core of the circuit is a relaxation oscillator whose oscillating frequency programmability resorts to variations neither in capacitor values nor in the sampling frequency. As a result, total capacitor area is reduced and, hence, area can be minimized while low phase jitter and high-resolution programmability are achieved. Simulation results considering the design and the implementation of an SC oscillator in a 0.35-mum CMOS process are presented to demonstrate the feasibility of the proposed approach.