Patent ID: 7782143

Claim:
A control circuit comprising: A phase detector that receives a reference phase φ REF (signal) as an input and a feedback phase φ FBK (signal) as control feedback; A voltage controlled oscillator (VCO) in electrical communication with the phase detector, the VCO providing an output and the feedback phase φ FBK (signal), the phase detector and the VCO forming at least a portion of a main loop; and An auxiliary feedback loop having a phase-frequency detector that, continuously and simultaneously with the phase detector of the main loop, receives the reference phase φ REF (signal) and the feedback phase φ FBK (signal), the auxiliary feedback loop continuously providing an adjustment signal to the main loop that corrects for static phase offset; wherein the auxiliary feedback loop includes a charge-pump and an input modulator that receives the reference phase φ REF (signal) and the feedback phase φ FBK (signal), the reference phase φ REF (signal) and the feedback phase φ FBK (signal) are compared to determine an error phase signal, the error phase signal is amplified by the phase-frequency detector and the charge-pump, and wherein an output of the charge-pump is rectified and filtered.