Patent ID: 6608524
Filing Date: 2003-08-19
Classification: H03G

Abstract:
An automatic gain control circuit, comprising:a variable gain amplifier for amplifying a reproduced signal from a recording medium; an A/D converter for quantizing the reproduced signal, which has been amplified by the variable gain amplifier; a clock generation circuit for generating a clock that is synchronized with the reproduced signal, which has been quantized by the A/D converter; an error calculation section for generating an error signal according to a difference between the reproduced signal, which has been quantized by the A/D converter, and one of n values (n is a positive integer) that corresponds to the reproduced signal, which has been quantized by the A/D converter, the n values being determined by a recording constraint and a recording format for the recording medium and a method for weighting the reproduced signal from the recording medium; and a control signal generation circuit for generating a gain control signal based on the error signal generated by the error calculation section, wherein: the A/D converter quantizes the reproduced signal, which has been amplified by the variable gain amplifier, in synchronism with the clock from the clock generation circuit; and the variable gain amplifier amplifies the reproduced signal from the recording medium with a gain according to a level of the gain control signal from the control signal generation circuit.