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:
Feb. 19, 2013
Filed:
Mar. 03, 2011
Kiyoshi Ishikawa, Kawasaki, JP;
Kiyoshi Ishikawa, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An analog-to-digital (AD) converter device, includes: a capacitive digital-to-analog converter (DAC) including a reference capacitor group having capacitors which are weighted with a ratio, one terminal of each of the capacitors being coupled to a common signal line, the other terminal of each of the capacitors being coupled to one of reference power supplies via one of switches; a comparator to compare a voltage of the common signal line with a reference voltage; a successive approximation routine circuit to control the switches based on a comparison result of the comparator; an offset correction circuit to correct an offset of the comparator; and a DAC correction circuit to correct an error in a voltage change of the common signal line, the offset correction circuit and the DAC correction circuit performing a correction so that a residual offset of the comparator and a residual error of the capacitive DAC cancel.