The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 23, 2008
Filed:
Feb. 03, 2005
Konstantinos Manetakis, Caen, FR;
Nicolas Constantinidis, Cresserons, FR;
Konstantinos Manetakis, Caen, FR;
Nicolas Constantinidis, Cresserons, FR;
Silicon Laboratories Inc., Austin, TX (US);
Abstract
A charge pumped phase locked loop circuit (PLL) is disclosed that includes a phase detector for detecting the phase error between a reference clock and an output clock to generate a phase error signal. A charge pump is provided that is controlled by the phase error signal to either source current to an intermediate control node or to sink current therefrom. An isolation circuit maintains the intermediate control node at a virtual AC reference voltage such that it remains at substantially the same voltage during the sourcing of current thereto or sinking of current therefrom, the isolation circuit generating a control voltage on the output thereof to control the frequency of the output clock. A loop filter is provided for filtering the control voltage.