Patent ID: 7332972
Filing Date: 2008-02-19
Classification: H03L

Abstract:
1. A phase locking loop circuit, comprising: a phase and frequency detector for receiving an input reference signal, and a feedback signal; a voltage controlled oscillator having a first analogue voltage input for controlling a frequency produced from said voltage controlled oscillator according to a first proportionality coefficient and a second analogue voltage input, independent from said first analogue voltage input for controlling a frequency produced from said voltage controlled oscillator according to a second proportionality coefficient, different from said first proportionality coefficient; a first charge pump receiving a signal from said frequency and phase detector and delivering a first control signal to said first voltage input of said voltage controlled oscillator; a second charge pump receiving a signal from said frequency and phase detector and delivering a second control signal to said second voltage input of said voltage controlled oscillator; and a feedback path for feeding a correction signal back to said phase and frequency detector; wherein said first charge pump is connected directly to the first voltage input of the voltage controlled oscillator, without a filtering capacitor.