AGC CONTROL CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide an AGC control circuit employing digital signal processing to reduce its circuit scale that can easily control an amplifier with high accuracy for demodulation of a single side band communication system. SOLUTION: A DSP 8 receives an input signal that is converted into a digital signal by an analog/digital converter 2 and applies digital signal processing to the input signal. A logarithmic conversion means 6 in the DSP 8 decides the value of the input signal and adds an offset based on the decision result to the value of the input signal to logarithmically convert the input signal and to obtain an AGC control voltage that is logarithmically converted. Since the configuration of the logarithmic conversion means 6 is facilitated, the reduction in the scale of the AGC control circuit can be realized.