CORRECTION OF VOLTAGE OFFSET AND CLOCK OFFSET FOR SAMPLING NEAR ZERO-CROSSING POINT

摘要

Embodiments of a circuit are described. This circuit includes a receiver circuit including a first sampler (312-1) and a second" sampler (312-2). A clock-data-recovery circuit (324) in the receiver circuit adjusts a sample time of the receiver circuit so that the sample time is proximate to a signal crossing point at an edge of an eye pattern associated with received signals. An offset-calibration circuit (326) in the receiver circuit determines and adjusts an offset voltage of a given sampler, which can be the first sampler or the second sampler. This offset-calibration circuit may determine a present offset voltage (412) of the given sampler in a timing region proximate to the signal crossing point (410-2) in which the clock-data-recovery circuit dithers about a present sample time based on the present offset voltage. Additionally, the clock-data-recovery circuit and the offset-calibration circuit may iteratively converge on the signal crossing point and a residual offset voltage of the given sampler.