Patent ID: 6035409
Filing Date: 2000-03-07
Classification: H03L,H04L

Abstract:
A clock recovery circuit comprising:a series of delay elements controlled by a delay locked loop and a digital-to-analog converter such that each delay element produces a clock signal that is phase delayed from the previous delay element in the series by a defined phase difference;a phase interpolator that provides an input clock signal to the series of delay elements;a series of phase detectors that are interleaved such that the first phase detector in the series uses the incoming clock signal as a clock retarded one phase, the output of the first delay element as a clock signal and the output of the second delay element as a clock advanced one phase, the second phase detector in the series uses the output of the second delay element as a clock retarded one phase, the output of the third delay element as a clock signal and the output of the fourth delay element as a clock advanced one phase, this pattern of inputs from the delay elements being repeated for each of the phase detectors such that each phase detector provides a phase error output and a data output;a data analyzer and converter that samples the data outputs from the phase detectors and provides a corresponding multi-bit recovered data vector;a phase sampler and majority voter block that provides a pumpup/pumpdown pulse stream based upon the phase error outputs of the phase detectors; anda pulse density attenuator and integrator block that converts the pumpup/pumpdown pulse stream from the phase sampler and majority voter block to a pulse stream that is used to advance and retard the phase of the clock signal provided by the phase interpolator to the series of delay elements.