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.

Date of Patent:
Sep. 19, 2006

Filed:

Sep. 16, 2005
Applicants:

Junji Hayakawa, Okazaki, JP;

Norio Kitao, Shinshiro, JP;

Akinobu Umemura, Nagoya, JP;

Hirokazu Ito, Oobu, JP;

Takaaki Kawai, Oobu, JP;

Inventors:

Junji Hayakawa, Okazaki, JP;

Norio Kitao, Shinshiro, JP;

Akinobu Umemura, Nagoya, JP;

Hirokazu Ito, Oobu, JP;

Takaaki Kawai, Oobu, JP;

Assignee:

Denso Corporation, Kariya, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R 27/26 (2006.01); G01P 21/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

In a capacitive physical quantity sensor, a C-V converter converts a variation in a capacitance between a movable electrode and a fixed electrode into a voltage to output the converted voltage in a first operating mode. The C-V converter also outputs a constant voltage in a second operating mode. An amplifier amplifies the converted voltage to output a first voltage, and amplifies the constant voltage to output a second voltage. A first sample and hold circuit operates in the first operating mode to sample and hold the first voltage. A second sample and hold circuit operates in the second operating mode to sample and hold the second voltage. A first differential amplifier obtains a difference voltage between the first voltage held by the first sample and hold circuit and the second voltage held by the second sample and hold circuit.


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