发明名称 |
AGC circuit and recording and reproducing apparatus using AGC circuit |
摘要 |
An AGC circuit is provided with a variable gain amplifier which changes an amplification gain of an input signal in accordance with an instruction; an extraction unit for extracting a value of an output of the variable gain amplifier at a predetermined interval; and a variable gain control unit for instructing the amplification gain of the variable gain amplifier in a manner such that the amplitude of the input signal is equal to a predetermined amplitude on the basis of the value extracted by the extraction unit. The variable gain control unit is provided with an error signal output device for squaring the value extracted by the extraction unit and for generating an error signal to instruct the amplification gain of the variable gain amplifier in a manner such that the amplitude of the input signal is equal to a predetermined amplitude on the basis of the square value and a square value just before it; and an integrating device for integrating the error signal from the error signal output device and for instructing the amplification gain of the variable gain amplifier.
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申请公布号 |
US5448424(A) |
申请公布日期 |
1995.09.05 |
申请号 |
US19940196478 |
申请日期 |
1994.02.15 |
申请人 |
HITACHI, LTD. |
发明人 |
HIRANO, AKIHIKO;TAKASHI, TERUMI;IWABUCHI, KAZUNORI;YAMAKAWA, HIDEYUKI;ISHIDA, YOSHITERU;KOSUGE, MINORU |
分类号 |
G11B5/09;G11B20/04;G11B20/10;G11B20/12;G11B20/14;H03G3/00;H03G3/20;H03G3/30;H03G11/00;(IPC1-7):G11B5/035 |
主分类号 |
G11B5/09 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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