Adjustment of the duty-cycle of a periodic digital signal with leading and triling edge DLLs

摘要

A signal processing circuit includes a first delay locked loop (DLL) circuit that generates a first intermediate output signal in response to an input signal and a phase difference between a leading edge of a reference signal and a leading edge of a feedback signal and a second DLL circuit that generates a second intermediate output signal in response to the input signal and a phase difference between a trailing edge of the reference signal and a trailing edge of the feedback signal. Because the first and second intermediate output signals are based on the phase difference between the reference signal and the leading and trailing edges of a feedback signal, respectively, and the first and second intermediate output signals are not derived from the reference signal, the jitter that may be introduced into the first and second intermediate output signals may be reduced.