Patent ID: 6741846
Filing Date: 2004-05-25
Classification: H03L

Abstract:
A frequency synthesizer having a phase locked loop, comprising:a controllable oscillator having an output frequency dependent upon a plurality of control signals, the plurality of control signals being received by the controllable oscillator as different frequency control input signals such that at least some of the plurality of control signals are configured to individually control the controllable oscillator without being combined with others of the plurality of control signals; a phase detector configured to concurrently provide a plurality of analog output signals, the plurality of analog output signals being generated from a phase difference between at least two input signals; and a sample and hold circuit coupled to sample each of the plurality analog output signals from the phase detector and to hold a plurality of sampled analog output signals, the sampled analog output signals being used to provide the plurality of control signals for the controllable oscillator; wherein the controlled oscillator comprises a plurality of capacitor circuits connected in parallel to contribute a combined capacitance amount that determines at least in part the output frequency of the controlled oscillator, the plurality of control signals being coupled to control the amount of capacitance contributed by the plurality of capacitor circuits.