Patent ID: 7750744

Claim:
An electronic circuit comprising: a phase frequency detector (PFD) receiving a reference clock signal and a feedback signal and providing a PFD output; a charge pump having an input coupled to the PFD output and which generates a single-ended output signal; a filter having an input coupled to the single-ended output signal and which generates a filtered single-ended output signal; a voltage controlled oscillator (VCO) which generates the feedback signal received by the PFD; and a common-mode feedback (CMF) circuit, having a replica circuit and an error amplifier and which: (a) receives a single-ended output signal from the charge pump; (b) derives a complementary voltage of the single-ended output to form a differential voltage signal; and (c) centers the differential voltage about a common-mode level; and (d) derives a common-mode feedback signal by providing the single-ended output signal from the charge pump and an error amplifier output as inputs to the replica circuit, which derives a common-mode feedback signal.