Patent ID: 6975840

Claim:
A charge pump of a local oscillator of a radio transceiver, the charge pump for sinking current from and sourcing current to an output node, the charge pump comprising: a first current module for generating a source current for transmission into the output node; a second current module for sinking a current from the output node; a first current mirror module for adjusting current flow generated by the first current module, the first current mirror module including a first current flow component coupled in series between the first current module and the output node; a second current mirror module for defining a fixed amount of current that is sinked from the output node, the second current mirror module including a second current flow component coupled in series between the output node and the second current module; a first feedback module coupled to a second component of the first current mirror module, the first feedback module also coupled to the output node, the first feedback module for prompting the first current flow component of the first current mirror module to decrease the magnitude of the source current produced by the first current module responsive to a decrease in an output voltage; and a second feedback module coupled to the output node and to the first feedback module and coupled in series with a branch component of the second current mirror module that, in turn, is coupled in series with the second component of the first current mirror module, the second feedback module for prompting the second component and the first current flow component, both of the first current mirror, to increase the magnitude of the source current produced by the first current module responsive to an increase in the output voltage.