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. 08, 2020
Filed:
Aug. 31, 2016
Hitachi, Ltd., Chiyoda-ku, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The present invention is directed to a CV conversion amplifier which is small in current consumption and capable of securing a sufficient capacitance-voltage conversion gain and a sufficient amplitude range of an output voltage and a capacitive sensor using the same which is low power consumption, low in noise, and wide in an input signal allowable range. A capacitive sensor includes first and second detection capacitors, a CV conversion circuit includes first and second feedback capacitors and obtains a voltage based on capacitance values of the first and second feedback capacitors, an AD converter performs analog digital conversion on an input voltage and obtains a digital signal, a digital control unit receives the digital signal as an input, and first and second digitally controlled variable capacitors have capacitance values that are controlled by the digital control unit.