Patent ID: 7177611

Claim:
A hybrid digital and analog phase locked loop, comprising: a voltage controlled oscillator having a fine tune input, a coarse tune input and an output; a frequency divider having an input connected to receive a signal provided by the output of the voltage controlled oscillator, and having an output for providing a signal having a frequency that is scaled with respect to a signal provided to its input; a phase detector connected to receive a reference input signal having a reference frequency at a first input thereof and connected to receive the a signal provided by the output of the frequency divider, and having an output for providing a phase error signal; an analog circuit configured as a proportional filter connected to receive the phase error signal and to provide a fine tune signal at the fine tune input of the voltage controlled oscillator; and a digital integrator connected to receive the phase error signal and to provide a coarse tune signal at the coarse tune input of the voltage controlled oscillator.