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:
Aug. 28, 2007
Filed:
Apr. 18, 2005
Toshio Adachi, Yokohama, JP;
Toshio Adachi, Yokohama, JP;
Asahi Kasei Microsystems Co., Ltd., Tokyo, JP;
Abstract
The present invention is a folded cascode operational amplifier provided with a differential input portion, cascode current source portion, current mirror portion, output portion, and differential amplifierserving as a differential amplifying portion. The differential input portionhas P-type MOS transistors Mand Mof a differential pair for respectively inputting a differential signal and the MOS transistors Mand Mare respectively provided with a well terminal. The differential amplifiercompares the source voltage of each of the MOS transistors Mand Mwith a predetermined reference voltage Vref, generates an output voltage in accordance with the comparison result, and supplies the generated output voltage to well terminals as well voltages of the MOS transistors Mand M. An operational amplifier is provided which performs the rail-to-rail operation at a low voltage and in which an input current is zero.