Method for re-centering a VCO, integrated circuit and wireless device

摘要

A method of re-centering a voltage controlled oscillator of a wireless device comprising a phase locked loop circuit is described. The method comprises receiving an input frequency signal at a phase detector of the phase locked loop circuit from a frequency source; generating an oscillator signal based on the received frequency signal; selectably opening a feedback loop of the phase locked loop circuit when in a calibration mode of operation, performing coarse frequency tuning of the oscillator output signal; performing fine frequency tuning of a coarsely adjusted oscillator output signal; and closing the feedback loop.

主权项

1. A method of re-centering a voltage controlled oscillator of a wireless device comprising a phase locked loop circuit, the method comprising:
receiving an input frequency signal at a phase detector of the phase locked loop circuit from a frequency source; generating an oscillator signal based on the received frequency signal; selectably opening a feedback loop of the phase locked loop circuit when in a calibration mode of operation; performing coarse frequency tuning of the oscillator output signal, wherein performing coarse frequency tuning comprises applying a coarse tuning control signal to switch a number of selectable first capacitive elements in the coarse tuning capacitive circuit in or out of the oscillator, and wherein applying the coarse tuning control signal comprises switching selectable first capacitive elements in or out of the oscillator until a first minimum oscillator frequency error is determined, and fixing the coarse tuning capacitive circuit arrangement with the first minimum determined oscillator frequency error; performing fine frequency tuning of a coarsely adjusted oscillator output signal, wherein performing fine frequency tuning comprises applying a fine tuning control signal to switch a number of selectable second capacitive elements in a fine tuning capacitive circuit in or out of the oscillator; and closing the feedback loop.