Patent Number: 7,088,962

Title: On-chip loop filter for a PLL

Abstract: An on-chip loop filter includes a resistor, a capacitor, a 2.sup.nd capacitor, a 3.sup.rd capacitor, a 2.sup.nd resistor, and a capacitor. The resistor is operably coupled to receive a charge pump output. The capacitor is coupled in series with the resistor where the second node of the capacitor is coupled to a return. The 2.sup.nd capacitor is coupled in parallel with the series combination of the resistor and capacitor. The 3.sup.rd capacitor is coupled in parallel with the 2.sup.nd capacitor. The 2.sup.nd resistor is coupled to a node of the 3.sup.rd capacitor and to a node of the capacitor. The other node of the capacitor is coupled to ground. To enable these components to be placed on-chip, the capacitor is of a capacitor construct having a quality factor, the 2.sup.nd capacitor is of a 2.sup.nd capacitor construct having a 2.sup.nd quality factor, where the 2.sup.nd quality factor is greater than the quality factor, and the 3.sup.rd and capacitors are of a 3.sup.rd capacitor construct having a 3.sup.rd quality factor, which is greater than the 2.sup.nd quality factor.

Inventors: Anand; Seema B. (Beverly Hills, CA), Wu; Stephen (Fountain Valley, CA)

Assignee: Broadcom Corporation

International Classification: H04B 1/40 (20060101); H04B 1/06 (20060101); H04B 7/00 (20060101)

Expiration Date: 8/08/02018