Patent ID: 6933789

Claim:
In a phase-locked loop (PLL) disposed on a circuit chip and including a synthesizer, a voltage-controlled oscillator (VCO) calibration system disposed on the circuit chip comprising: an input configured to receive a tuning voltage; a plurality of VCOs in a set of VCOs, each VCO including a plurality of selectively coupled varactors; a tuning-voltage-distribution circuit configured to couple the input to the VCOs; and a calibration circuit coupled to at least one of the power distribution circuit and the set of VCOs and configured to control tuning voltage distribution from the input to selective varactors of each VCO, to determine a selected VCO of the set of VCOs that is capable of producing a desired range of frequencies in response to tuning voltages within a desired range of tuning voltages, and to determine a desired combination of the varactors to use in the selected VCO to produce the desired range of frequencies in response the tuning voltages within the desired range of tuning voltages.