Clock signal synchronizing device with inherent duty-cycle correction capability

Abstract

One aspect relates to a clock signal synchronizing device, in particular to a delayed locked loop (DLL) with capability to correct static duty-cycle offset and to filter clock-jitter. One aspect relates to a clock signal synchronizing method with capability to correct static duty-cycle offset and to filter clock-jitter. In accordance one aspect, there is provided a clock signal synchronizing device including a delay circuit having a variable delay time and delaying an incoming clock signal or a signal generated therefrom to output a delayed clock signal. Also included is a negator for inverting the delayed clock signal to output an inverted delayed clock signal. Also included is a delay control circuit for controlling the delay circuit to adjust the phase relation between the incoming clock signal and the inverted delayed clock signal and a phase interpolator. The phase interpolator is activated when the incoming clock signal and the inverted delayed clock signal are substantially in phase and adds the incoming clock signal multiplied with a factor of substantially (1−p) to the inverted delayed clock signal multiplied with a factor of substantially p to output a compound signal to the delay circuit, p being a real number greater than or equal to 0 and smaller than or equal to 1.