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. 12, 1998
Filed:
Oct. 28, 1996
Masahiro Tsugai, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In a switched-capacitor type interface circuit connected to a capacitive sensor having two capacitors (C1, C2) whose value is variable, the interface circuit includes an operational amplifier (A1) with an output terminal and an inverting input terminal between which a feedback/sampling capacitor (C3) is connected, and a holding capacitor (C4) connected between the operational amplifier (A1) and a reference voltage source. The capacitors (C1, C2, C3) have one ends connected to the inverting input terminal of the operational amplifier (A1). The other ends of the capacitors (C1, C2) are connected to a power source and the capacitor (C3) is concurrently short-circuited depending upon predetermined timing, and the other ends of the and capacitors (C1, C2) and the output terminal of the operational amplifier (A1) are respectively connected to a non-inverting input terminal of the operational amplifier (A1) after the elapse of a predetermined time from the predetermined timing.