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:
May. 03, 2005
Filed:
Jan. 07, 2004
Minoru Itoh, Shiga-ken, JP;
Minoru Itoh, Shiga-ken, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An input changing switch is provided at a preceding stage of a comparator that measures a DC offset of a D/A converter, and also a selective polarity inverting circuit is provided at a subsequent stage. A first compensation value is generated by a compensation value generating means and then stored in a register. Then, a second compensation value is generated by switching the input changing switch and the polarity inverting circuit and then stored in a register. Then, a third compensation value is calculated by averaging the first compensation value and the second compensation value by a compensation value calculating circuit. Then, the DC offset of the D/A converter is compensated by using this compensation value. Therefore, it enables to implement a precise DC offset compensation of the D/A converter by canceling the DC offset contained in the comparator itself employed in the DC offset compensation of the D/A converter.