Patent ID: 6940324

Claim:
A phase lock loop circuit, comprising: a first charge pump circuit, a second charge pump circuit, and a loop filter circuit within the phase lock loop circuit, the first charge pump circuit comprising a first adjustable gain, the second charge pump circuit comprising a second adjustable gain, the loop filter circuit comprising a filter capacitor with a constant capacitance value C, the first charge pump circuit being electrically connected to the loop filter circuit, the second charge pump circuit being electrically connected to the loop filter circuit in parallel with the filter capacitor, the first charge pump circuit being adapted to source a first current to said loop filter circuit, the second charge pump circuit being adapted to source a second current to said loop filter circuit, the first charge pump circuit and the second charge pump circuit being adapted to collectively decrease an effective capacitance value C eff of the filter capacitor by adjusting said first adjustable gain to a first gain value G m and said second adjustable gain to a second gain valueG a , the effective capacitance value C eff being determined by an equation C eff =(C*G m )/(G m =G a ), and the loop filter being adapted to provide a voltage for a voltage controlled oscillator.