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:
Jan. 22, 2019
Fuji Electric Co., Ltd., Kawasaki, JP;
Motomitsu Iwamoto, Matsumoto, JP;
FUJI ELECTRIC CO., LTD., Kawasaki, JP;
Abstract
An operational amplifier circuit includes a potential control circuit connected between a current sense semiconductor element connected in parallel with a main semiconductor element and a current detection resistor. The potential control circuit controls an output potential of the current sense semiconductor element to be equal to that of the main semiconductor element. The potential control circuit includes a current control element controlling an output current of the current sense semiconductor element and an operational amplifier outputting a signal corresponding to an output potential difference between the current sense semiconductor element and the main semiconductor element to the current control element. An input offset voltage polarity determination unit determines a polarity of an input offset voltage of the operational amplifier according to the output potential difference. The polarity of the input offset voltage is controlled to be constant based on polarity determination of the input offset voltage.