Method and apparatus for phase rotation in a phase locked loop

摘要

Among a plurality of signals, each phase-shifted with respect to the others, one signal is repeatedly substituted for another as a clock signal, to reduce a phase error of the clock signal with respect to a reference clock. The substitutions are timed to occur during intervals tending to reduce disturbances to the clock signal. Also, such substitution of a signal is responsive to occurrence of at least one cycle of the signal subsequent to the clock being supplied by an immediate predecessor of the signal, which tends to prevent erroneous substitutions of one signal for another.