Patent · US Active

Digitally programmed capacitance multiplication with one charge pump

US8760201B1 · kind B1 · utility

3Cited by

4References

20Claims

0Family size

Assignee

ANALOG DEVICES TECHNOLOGY · BM

Inventors

Ting Gao · Sunnyvale, US
Jiefeng Yan · Shanghai, CN

Key dates

Filing date	Mar 11, 2013
Grant date	Jun 24, 2014
Priority date	—
Expiry date	Mar 11, 2033

Classification

Technology area (CPC H)Electricity
CPC primaryH03L7/0895
WIPO fieldBasic communication processes
WIPO sectorElectrical engineering

Abstract

Systems and methods for capacitance multiplication using one charge pump for a phase lock loop employ a digital controlled loop filter that operates in a time division mode. Embodiments of the loop filter block the current from the charge pump according to the digital control, such that the charge pump cannot charge or discharge the integral capacitor when the digital control is enabled. Because at least a portion of the current is blocked, it takes more time for the charge pump to charge or discharge the capacitor to a certain level. The capacitor then appears to be larger than its actual value with respect to operation of the phase lock loop.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.