| US 7,525,383 B2 | ||
| Differential amplifier | ||
| Shigeto Kobayashi, Gifu (Japan); and Atsushi Wada, Ogaki (Japan) | ||
| Assigned to Sanyo Electric Co., Ltd., Osaka (Japan) | ||
| Filed on Sep. 24, 2007, as Appl. No. 11/902,557. | ||
| Claims priority of application No. 2006-266815 (JP), filed on Sep. 29, 2006; and application No. 2007-202287 (JP), filed on Aug. 02, 2007. | ||
| Prior Publication US 2008/0079492 A1, Apr. 03, 2008 | ||
| Int. Cl. H03F 3/45 (2006.01) | ||
| U.S. Cl. 330—261 [330/253] | 9 Claims |
| 1. A differential amplifier, comprising:
a differential transistor pair;
at least one current source connected to said differential transistor pair;
a bias circuit which supplies a bias voltage to said current source and which controls current generated by said current source;
a first self-bias switch and a second self-bias switch each provided between an input terminal and an output terminal of each
of transistors that constitute said differential transistor pair; and
an external bias switch provided on a path of bias voltage supplied from said bias circuit to said current source.
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