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:
Dec. 03, 1985
Filed:
Aug. 11, 1983
Kazuji Yamada, Hitachi, JP;
Hideo Sato, Hitachi, JP;
Kazuo Kato, Ibaraki, JP;
Takao Sasayama, Hitachi, JP;
Kanji Kawakami, Katsuta, JP;
Ryosaku Kanzawa, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A pressure transducer is disclosed comprising a pressure sensor portion having gage resistors in bridge formed on a thin diaphragm of a semiconductor substrate, and a power supply connected to the pressure sensor portion for driving the pressure sensor. The power supply includes a first current source for supplying a temperature-dependent current equivalent to the sum of a current almost proportional to the absolute temperature and a current independent of temperature, and a second current source for sinking the current almost proportional to the temperature characteristic of the gage resistors from the current of the first current source. A temperature compensation circuit is additionally provided to drive the bridge circuit by the difference between the temperature-dependent current and the current proportional to the temperature characteristic in a constant-current driving mode, and by a voltage proportional to the current difference when the output of the bridge circuit is connected to an amplifier whose gain is dependent on temperature.