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. 19, 2000
Filed:
Dec. 01, 1999
Takashi Hashimoto, Ome, JP;
Yuji Nagaya, Owariasahi, JP;
Masaki Yoshinaga, Higashiyamato, JP;
Noriaki Hatanaka, Chigasaki, JP;
Tatsuo Mochizuki, Yokohama, JP;
Katsuya Sonoyama, Akishima, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi ULSI Systems Co., Ltd., Tokyo, JP;
Hitachi Information Technology Co., Ltd., Kanagawa, JP;
Abstract
A very-small-signal amplifier is capable of amplifying very small signals with high sensitivity up to high frequencies while simplifying the circuit, and a magnetic disk storage apparatus realizes a reading operation over a wide band up to high frequencies with high sensitivity. The signal amplifier is a modified differential circuit including a first transistor of a first conductivity type and a second transistor of a second conductivity type each having a control terminal, a terminal of the input side and a terminal of the output side. The terminals on the input side are connected in common, and a current corresponding to the voltage difference across the control terminals is allowed to flow. A very small voltage signal generated by an input signal source is applied to the control terminal of said first transistor. A bias voltage is applied to the control terminal of the second transistor. Therefore, an amplified signal corresponding to the very small voltage signal generated by the input signal source is generated at the terminal on the output side of the second transistor.