APPARATUS FOR CORRECTING DUTY CYCLE AND ITS METHOD, IN WHICH A SIMPLE COMPARATOR INSTEAD OF AN ANALOG DIGITAL CONVERTER IS USED

摘要

PURPOSE: An apparatus for correcting a duty cycle and its method are provided, which replaces an analog digital converter through a simple comparator and operates independently as to a delay locked loop circuit. CONSTITUTION: The digital duty cycle correction apparatus generates the first internal clock and the second internal clock by correcting each duty of the first external clock and the second external clock. A duty detector(804) generates the first control voltage and the second control voltage according to each duty of the first and the second internal clock. A comparator(806) compares the first control voltage with the second control voltage. A counter(808) performs counting in response to an output of the comparator. A digital/analog converter(810) generates the third and the fourth control voltage by converting the digital code value being output from the counter into an analog signal. And a duty corrector(802) generates the first and the second internal clock by correcting duties of the first and the second external clock using the control voltages.