Patent ID: 7737795

Claim:
A voltage-controlled oscillator (VCO), comprising: a plurality of delay cells in a ring configuration, wherein each of the plurality of delay cells includes: a pair of differential bias voltage inputs; a source-coupled input transistor pair configured to receive a pair of differential voltage inputs; a pair of load resistors coupled to the source-coupled input transistor pair and configured to provide differential voltage outputs; a first common-mode feedback transistor having a gate coupled to a first output of the differential voltage outputs and a source and drain in series with a first of the pair of load resistors; a second common-mode feedback transistor having a gate coupled to a second output of the differential voltage outputs and a source and drain in series with a second of the pair of load resistors; and a current-steering transistor pair coupled to the source-coupled input transistor pair; wherein the VCO is configurable to have an output frequency that is based at least on bias voltages applied to the differential bias voltage inputs.