| 摘要 |
PROBLEM TO BE SOLVED: To provide a gain control circuit which constitutes a high-accuracy variable gain amplifier with a small gain variation due to the temperature or power voltage change. SOLUTION: A first variable gain amplifier 3a having the same constitution as a second variable gain amplifier 3b for amplifying input signals amplifies a reference signal. A first detector 4a detects an output signal from the first amplifier 3a and a second detector 4b detects the reference signal. A differential amplifier 5 amplifies the difference signal between output signals of the first and second detectors 4a, 4b to control the first and second variable gain amplifiers 3a, 3b according to the amplified difference signal. COPYRIGHT: (C)2004,JPO
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