Patent ID: 6792042
Filing Date: 2004-09-14
Classification: H02M

Abstract:
A pulse width modulation control system, comprising:an up counter and a down counter, each of which outputs a voltage value, wherein the voltage value is a chopping wave crossed at its maximum voltage value and minimum voltage value after receiving a clock input; an adder which sequentially adds the voltage value generated from the up counter; a subtracter which sequentially subtracts the voltage value generated from the down counter; a reference voltage value generation unit which outputs two different reference voltage values after receiving the voltage values outputted from the adder/subtracter and a reference voltage value set by a user; a comparator which separately compares the reference voltage values generated from the reference voltage value generation unit with voltage values outputted from the adder and subtracter, respectively, and generates an output voltage value; and an output control unit which outputs a PWM positive signal and a PWM negative signal in accordance with output voltage value of the comparator.