Patent attributes
A phase difference detector having concurrent fine and coarse capabilities synchronizes operations of coarse and fine phase detectors. In one embodiment, clusters of fine timing markers are generated by delay stages of a delay locked loop. The K'th one of every cluster of J fine timing markers is designated as a coarse marker. A first timer determines which of J fine markers in a first cluster is closest to a rising edge of a reference signal. A second timer determines which of J fine markers in a second cluster is closest to a rising edge of a follower signal. A third timer determines how many coarse markers separate the rising edges of the reference and follower signals. Temporal displacement values obtained from the determinations of the first though third timers are combined to produce a phase displacement measurement signal of broad range and high precision across its operating range.
