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. 06, 1997
Filed:
Feb. 06, 1996
Koji Sushihara, Iizuka, JP;
Takashi Yamamoto, Iizuka, JP;
Ikuo Imanishi, Nagaokakyo, JP;
Tsuyoshi Nakamura, Iizuka, JP;
Michinori Kishimoto, Iizuka, JP;
Kenichi Ishida, Iizuka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An amplifier circuit for amplifying a change in a resistance value of a magnetic resistance element is formed by connecting a first and a second current mirror circuits having the same structure in cascode, so that a voltage change is amplified without using a capacitive coupling. Hence, a high-pass filter is not created as a parasitic circuit, whereby a gain is maintained high in the low frequency region and a low frequency characteristic is excellent. Further, since control electrodes of transistors which form each current mirror circuit are grounded through the capacitance, a noise is reduced without using a conventional feedback circuit. This eliminates an influence of the feedback circuit over a high frequency characteristic, and therefore, a high frequency characteristic becomes excellent.