Patent ID: 6731712
Filing Date: 2004-05-04
Classification: H03J,H03L

Abstract:
A phase-locked loop frequency synthesizer comprising:a phase/frequency detector that compares a reference frequency with an output frequency signal and generates an appropriate charge pump control voltage; a programmable charge pump coupled to said phase/frequency detector that generates a loop filter control current from the charge pump control voltage; a loop filter coupled to said charge pump that generates a loop filter voltage; an oscillator bank coupled to the loop filter comprising a plurality of voltage controlled oscillators; a feedback circuit coupled between said oscillator bank and said phase/frequency detector that provides the output frequency to the phase/frequency detector; and a logic interface coupled to said oscillator bank for enabling one of said voltage controlled oscillators at a time, and coupled to the charge pump for programming the output current and output polarity of the charge pump as required by the enabled voltage controlled oscillator.