Patent ID: 8829962

Claim:
A charge pump for converting at least one of: a phase and a frequency difference into a control voltage, the charge pump comprising: a first current component coupled between a voltage supply and a first output node; a second current component coupled between the voltage supply and a second output node, a control node of the first current component being coupled to a control node of the second current component; a common mode feedback circuit including a first input coupled to the first output node, a second input coupled to the second output node, and an output coupled to the control nodes of the first and second current components; wherein a first bias current source supplies a first tunable bias current directly to the first output node and switchably supplies a first constant bias current to the first and second output nodes, and a second bias current source supplies a second tunable bias current directly to the first output node and switchably supplies a second constant bias current to the first and second output nodes.