Ciena Corporation
Phase skipping technique for high-speed, high-phase number delay locked loop

Abstract:

A delay locked loop (DLL) circuit includes inputs from M-phase clocks, M is an integer that is greater than or equal to 1; N delay cells in each of M separate delay lines, one delay line for each of the inputs from the M-phase clocks, and each of the N delay cells having a delay of k*.DELTA.t, N is an integer, and k is an integer that is coprime with both N and M; N outputs for clock phases from the N delay cells; and an alignment circuit connected to outputs of the M separate delay lines and the inputs from the M-phase clocks and configured to provide phase locking.