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:
Feb. 28, 2017
Filed:
Dec. 03, 2013
National Institute of Advanced Industrial Science and Technology, Tokyo, JP;
Shinichi Ouchi, Ibaraki, JP;
Abstract
There is provided an operational amplifier which is operable as well when an operating voltage decreases without creating a range where a circuit would not operate or reducing circuit gain. High-pass filters-provide output signals therefrom to bias-set input nodes of differential amplifiers Gm-Gmto a potential within a common-mode range in which the respective differential amplifiers Gm-Gmare operable. In this manner, the respective differential amplifiers Gm-Gmcan be operated effectively regardless of the possible decrease in a supply voltage, enabling normal amplifying operation. In addition, reduction in gain due to the reduced operational voltage is avoided. Therefore, it is preferably applicable to the application where digital and analog circuits are loaded together on the same IC chip. When a high-pass filter is required at each input side of two- or more-stage differential amplifiers, a phase compensation method utilizing multiple paths is provided for a lower range of a phase margin created at the low frequency side, enabling normal amplitude operation.