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.

Date of Patent:
Nov. 25, 2014

Filed:

Jan. 29, 2013
Applicant:

Semiconductor Technology Academic Research Center, Kanagawa, JP;

Inventors:

Tetsuya Hirose, Hyogo, JP;

Yuji Osaki, Hyogo, JP;

Yumiko Tsuruya, Hyogo, JP;

Osamu Kobayashi, Kanagawa, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F 3/45 (2006.01); H03F 3/30 (2006.01); H03F 1/02 (2006.01);
U.S. Cl.
CPC ...
H03F 3/45179 (2013.01); H03F 2203/45626 (2013.01); H03F 3/3028 (2013.01); H03F 3/45183 (2013.01); H03F 2203/45454 (2013.01); H03F 2203/45244 (2013.01); H03F 1/0261 (2013.01); H03F 2203/30021 (2013.01);
Abstract

A differential amplifier circuit includes a differential operational amplifier that includes a differential pair circuit and operates based on a constant bias current supplied from a bias current source circuit, and the differential amplifier circuit includes a bias current generator circuit. A current monitor circuit detects two currents flowing through the differential pair circuit in correspondence with differential input voltages inputted to the differential pair circuit, and detects a minimum current of the two currents for a difference voltage of the differential input voltages as a monitored current. A current comparator circuit compares the monitored current with the constant bias current. A current amplifier circuit amplifies a voltage corresponding to the comparison result, and controls currents flowing through the differential pair circuit based on an amplified voltage, and the bias current generator circuit performs negative feedback adaptive control such that the bias current increases as the monitored current decreases.


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