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:
Sep. 15, 2009
Filed:
Sep. 06, 2007
Takeshi Yoshida, Hiroshima, JP;
Yoshihiro Masui, Hiroshima, JP;
Atsushi Iwata, Hiroshima, JP;
Kunihiko Gotoh, Kanagawa, JP;
Takeshi Yoshida, Hiroshima, JP;
Yoshihiro Masui, Hiroshima, JP;
Atsushi Iwata, Hiroshima, JP;
Kunihiko Gotoh, Kanagawa, JP;
Semiconductor Technology Academic Research Center, Kanagawa, JP;
Abstract
In a feedback amplifier circuit, a first switching device executes an auto-zero operation by inputting a signal outputted from an amplifier to an input terminal of the amplifier during an auto-zero operation interval prior to an amplification interval. A first capacitor accumulates and holds an offset voltage at the output terminal of the amplifier during the auto-zero operation interval, and cancels an offset voltage at the input terminal of the amplifier by an accumulated and held offset voltage during an amplification interval subsequent to the auto-zero operation interval. A second switching device grounds the feedback point of the feedback circuit during the auto-zero operation interval. A second capacitor blocks a DC voltage, and accumulates and holds an offset voltage at an output terminal of the amplifier, and cancels an offset voltage at an input terminal of the amplifier by the accumulated and held offset voltage during an amplification interval.