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. 19, 2009
Filed:
Oct. 26, 2007
Kouichi Nishimura, Kanagawa, JP;
Atsushi Shimatani, Kanagawa, JP;
Kouichi Nishimura, Kanagawa, JP;
Atsushi Shimatani, Kanagawa, JP;
NEC Electronics Corporation, Kawasaki, Kanagawa, JP;
Abstract
To reduce the apparent effect of offset voltage by making the offset voltage spatially scattered. An operational amplifierincludes: a first differential pair having N-channel MOS transistors MNand MN; a second differential pair having P-channel MOS transistors MPand MP; an output stage having output transistors NPand MN; first and second active loadsandhaving a switch, adapted to convert differential outputs from the first and second differential pairs to a single output, respectively; first and second bias circuitsandhaving a switch, adapted to select one of two outputs of each of the first and second active loadsandhaving the switch and to determine idling current of the MPand MN, respectively; first and second switches SWand SWadapted to respectively connect an output terminal and an input terminal to one of the gates of each of the first and second differential pairs; and a terminaladapted to receive an offset cancellation signal for controlling switching functions and the switches in linkage with each other.