Patent 7295053 was granted and assigned to Wolfson Microelectronics on November, 2007 by the United States Patent and Trademark Office.
A delay-locked loop (DLL) circuit comprises a voltage controlled delay line (VCDL) including a plurality of identical delay stages connected in series, and a feedback loop including a phase comparator for controlling the VCDL such that the total delay over a number of stages matches the period of the periodic reference signal. Signal outputs are connected to derive their respective output signals from respective nodes within the delay line. The phase comparator compares the phase of first and second differently delayed versions of the reference signal from respective nodes within the variable delay line separated only by a plurality of identical delay stages.