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. 12, 2002
Filed:
Jul. 02, 1999
Applicant:
Inventors:
Moises E. Robinson, Austin, TX (US);
Bernard L. Grung, Eden Prairie, MN (US);
Yiqin Chen, Ames, IA (US);
Assignee:
Xilinx, Inc., San Jose, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L 7/07 ; H03L 7/087 ;
U.S. Cl.
CPC ...
H03L 7/07 ; H03L 7/087 ;
Abstract
A high speed data communication system includes a receiver to recover data and clock signals from communicated data. The receiver circuit has a dual phase lock loop (PLL) circuit. A fine loop of the PLL includes a phase detector providing a differential analog voltage output. Transconductance circuitry converts the differential analog voltage output to a low current analog output. The transconductance circuitry has a variable gain which is controlled by an automatic gain adjust circuit. A coarse loop of the PLL allows for fast frequency acquisition of an internal oscillator.