Methods and Circuits for Duty-Cycle Correction

摘要

A duty-cycle correction circuit calibrates the duty cycle of a periodic input signal. The correction circuit includes a state machine that samples the input signal using a sample signal of a sample period. The sample period is selected to scan a period of the input signal over a number of sample periods. The resultant difference between the number of high and low samples provides a measure of the duty cycle deviation from e.g. 50%. An adjustable delay circuit adjusts the relative timing of the rising and falling edges of the input signal, and thus the duty cycle, responsive to the measure of duty cycle.