Pll frequency synthesizer

Abstract From the Canadian patent

Disclosed is a frequency synthesizer comprising: a voltage-controlled oscillator (VCO) for generating an oscillation of a frequency varying responsive to a control voltage; a variable frequency divider for dividing the output frequency of the VCO in a ratio according to a control signal; a reference oscillator for supplying a reference signal having a predetermined frequency; a fixed frequency divider for dividing the frequency of the reference signal in a fixed ratio; a phase comparator for comparing the phases of the outputs of the fixed frequency divider and variable frequency divider to provide a control pulse corresponding to a phase difference between these outputs; a charge pump …