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. 08, 2007
Filed:
Sep. 12, 2006
Masayuki Ozasa, Kyoto, JP;
Akio Yokoyama, Ibaraki, JP;
Masayuki Ozasa, Kyoto, JP;
Akio Yokoyama, Ibaraki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a differential amplifier and an operational amplifier each for amplifying a signal, a differential signal composed of first and second signals is inputted to a couple of input terminals (). When the voltage of the first signal is, e.g., less than the voltage value of a reference voltage source (), a comparator () senses it and a switch circuit () switches to a first current source () and a current from a third current source () flows into the first current source () so that a current is inhibited from flowing in the first differential couple (). As a result, the inputted differential signal is amplified and outputted only through a second differential couple (). In a situation in which the voltage of the first signal exceeds the voltage of the reference voltage source (), on the other hand, the switch circuit () switches to a current source () so that the inputted differential signal is amplified and outputted only through the first differential couple (). As a result, a gain is equal over the entire range of input operating voltage and a high-speed operation is performed.