Patent ID: 7088962

Claim:
An on-chip loop filter for a phase locked loop, the on-chip filter comprises: a first resistor having a first node and a second node, wherein the first node is operably coupled to receive a charge pump output; a first capacitor having a first node and a second node, wherein the first node of the first capacitor is operably coupled in series with the second node of the first resistor, wherein the second node of the first capacitor is coupled to a return, wherein the first capacitor is of a first capacitor construct having a first quality factor; a second capacitor operably coupled in parallel to the series connection of the first resistor and the first capacitor, wherein the second capacitor is of a second capacitor construct having a second quality factor, wherein the second quality factor is greater than the first quality factor; a third capacitor operably coupled in parallel with the second capacitor, wherein the third capacitor is of third capacitor construct having a third quality factor, wherein the third quality factor is greater than the second quality factor; a second resistor having a first node and a second node, wherein the first node of the second resistor is operably coupled to the first node of the first resistor; and a fourth capacitor having a first node and a second node, wherein the first node of the fourth capacitor is coupled to the second node of the second resistor to provide a control voltage, wherein the second node of the fourth capacitor is coupled to the return, wherein the fourth capacitor is of the third capacitor construct having the third quality factor.