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. 06, 2005
Filed:
Dec. 12, 2003
Masaharu Sato, Otsu, JP;
Takuma Ishida, Takatsuki, JP;
Taku Kobayashi, Suita, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In order that an amplifier with a gain proportional to source voltage is obtained, the drain-source voltages of first and second P-channel MOS-FETs are zero-biased, and a voltage shifted higher by the amount of the threshold voltage of the P-channel MOS-FET on the basis of a voltage obtained by dividing the power source voltage by resistors is applied to the positive input terminal of an operational amplifier. The gate of one of the first and second MOS-FETs is connected to a circuit ground, and a negative fixed voltage with reference to the potential obtained by dividing the power source voltage by resistors is applied to the gate of the other MOS-FET. The ON resistances of the two MOS-FETs are used as the input resistor and the feedback resistor of the operational amplifier, respectively.