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:
Jan. 14, 2003
Filed:
Aug. 14, 2001
Applicant:
Inventors:
Yvette P. Lee, Austin, TX (US);
Marwan N. Hassoun, Austin, TX (US);
Assignee:
Xilinx, Inc., San Jose, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03M 1/10 ;
U.S. Cl.
CPC ...
H03M 1/10 ;
Abstract
A current source calibration circuit and methodology reduce noise generated by current switching. In one embodiment, the calibration circuit provides a random or pseudo-random clock signal to control a switching of calibration circuit. A clock signal generator has been described that provide a number of clock signals having different phases. In one embodiment, the clock signals are used to select a current source of a DAC for calibration. By using a random clock to select the current source, noise, which is generated by switching a primary current source with a backup current source, is spread out over a wider frequency range.