Patent ID: 7583943
Filing Date: 2009-09-01
Classification: H03G

Abstract:
1. An automatic gain control device comprising: a first variable gain amplifier for amplifying an input signal; a filter for limiting a band of an output signal of the first variable gain amplifier; a second variable gain amplifier for amplifying an output signal of the filter; a third variable gain amplifier for amplifying and externally outputting the output signal of the filter; a first control signal generator for generating a first control signal to control a level of the output signal of the first variable gain amplifier to a predetermined level; a second control signal generator for generating a second control signal to control a level of an output signal of the second variable gain amplifier to a predetermined level and outputting the second control signal to the second variable gain amplifier; a third control signal generator, with a response characteristic that is faster than that of the second control signal generator, for generating a third control signal for controlling a level of an output signal of the third variable gain amplifier to a predetermined level and outputting the third control signal to the third variable gain amplifier; a control signal selector for selecting one of the first and second control signals generated from the first and second control signal generators and outputting the selected control signal to the first variable gain amplifier; and a reference information copier for copying control information of the second control signal generator into the first control signal generator when the control signal output from the second control signal generator is selected as the control signal for the first variable gain amplifier.