Wide-range high-precision pulsewidth control loop

Abstract

This work presents a wide range pulse-width control loop circuit. The input control stage is designed with ratioless circuit without dissipating dc power. The differential signals of the charge pump increase the accuracy of output duty cycle. The characteristics of complementary signals accomplished by a connection of differential second-order low-pass filter between complementary charge pumps can effectively increase the stability and reduce the capacitor area. This work introduces a new approach in receiving wide-range input and output duty cycles at an extended bandwidth. Simulation verifies that the duty cycle range of input and output clock is from 1% to 99% with resolution of 1%. © 2009 IEEE.