Patent ID: 8536912

Claim:
An apparatus comprising: a phase/frequency detector (PFD) that receives a reference signal; a charge pump that is coupled to the PFD; a first gain control circuit that is coupled to the charge pump, wherein the first gain control circuit has a first gain and a first response; a second gain control circuit that is coupled to the charge pump, wherein the second gain control circuit has a second gain and a second response, and wherein the second gain is greater than the first gain, and wherein the first response is greater than the second response; a summing circuit that is coupled to the first and second gain control circuits; and a voltage controlled oscillator (VCO) that is coupled to the summing circuit and the PFD, wherein the apparatus further comprises a divider that is coupled between the VCO and the PFD, wherein the first gain control circuit further comprises: a low pass filter (LPF) that is coupled to the charge pump; and a gain circuit that is coupled between the LPF and the summing circuit.