Patent ID: 7202752

Claim:
A phase locked loop comprising: a difference detection module operably coupled to determine a difference signal based on at least one of a phase difference and a frequency difference between a reference oscillation and a feedback oscillation; a loop filter module operably coupled to convert the difference signal into a control signal; a ring oscillator having a plurality of buffer stages and a plurality to taps coupled to a corresponding plurality of outputs of the plurality of buffer stages, the ring oscillator operably coupled to convert the control signal into an output oscillation; an output oscillation adjust module operably coupled to the ring oscillator for producing an effective output oscillation based on an oscillation control signal, wherein the output oscillation adjust module includes an output select block, operably coupled to the plurality of taps, for producing the effective output oscillation from a sequence of selected taps from the plurality of taps, and a tap adjust control generator, responsive to the oscillation control signal for generating a sequence of tap adjust control signals that command the output select block to select the sequence of selected taps from the plurality of taps; and a divider module operably coupled to convert the effective output oscillation into the feedback oscillation; wherein the effective output oscillation has a frequency F eo and the output oscillation has a frequency F o and wherein |F eo −F o |/F o <0.5; wherein the divider module is responsive to the oscillation control signal to produce the feedback oscillation by dividing the frequency of the effective output oscillation F eo by a selected divisor.