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:
Mar. 08, 2016
Filed:
Feb. 03, 2015
Applicant:
Hittite Microwave Corporation, Chelmsford, MA (US);
Inventors:
Gordon John Allan, Ottawa, CA;
Justin L. Fortier, Ottawa, CA;
Assignee:
Hittite Microwave Corporation, Chelmsford, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L 7/06 (2006.01); H03L 7/14 (2006.01); H03L 7/089 (2006.01); H03L 7/107 (2006.01); H03L 7/083 (2006.01); H03L 7/085 (2006.01); H03L 7/099 (2006.01);
U.S. Cl.
CPC ...
H03L 7/14 (2013.01); H03L 7/083 (2013.01); H03L 7/085 (2013.01); H03L 7/0891 (2013.01); H03L 7/099 (2013.01); H03L 7/1077 (2013.01);
Abstract
Provided herein are apparatus and methods for fast charge pump holdover on signal interruption. In certain configurations, a clock generator system includes a phase-locked loop (PLL), a fast detect circuit, and a switch electrically coupled to an input of the PLL's loop filter. The fast detect circuit relatively quickly detects when an input signal to the PLL is lost. The fast detect circuit can quickly detect the loss of phase lock and can place the PLL into a holdover such that the frequency of a clock signal generated by the PLL remains within an acceptable range.