Patent ID: 6885176

Claim:
A PWM regulator for receiving a square wave signal having a duty cycle and providing a regulated direct current (DC) signal at an output thereof and comprising: a switching device for modulating the duty cycle of the square wave signal; and a control circuit for controlling said switching device and comprising a detector for detecting trailing edges of the square wave signal and providing a reset signal based thereon, a ramp signal generator connected to said detector for generating a ramp signal based upon leading edges of the square wave signal, and for resetting the ramp signal based upon the reset signal, a first comparator connected to the output of the PMW regulator for comparing the regulated DC signal with a reference signal and providing an error signal based thereon, a second comparator for comparing the ramp signal with the error signal and providing a PMW signal based thereon, and a driver for receiving the PWM signal and providing a driving signal for driving said switching device .based thereon to control a conduction interval thereof, the driving signal having a duty cycle less than or equal to the duty cycle of the square wave signal and also having trailing edges coinciding with the trailing edges of the square wave signal.