Fronted circuit

摘要

A band-pass filter separates an audio intermediate frequency signal from an input intermediate frequency signal, and an A/D converter circuit converts the signal into a digital signal. A DSP performs audio detection on the signal and forms an AGC signal based on the signal. A variable gain amplifier performs AGC on the signal. A band-pass filter separates and takes out a video intermediate frequency signal from the signal, and an A/D converter circuit converts the signal into a digital signal. A DSP performs video detection on the signal. An AGC signal is formed based on the signals and AGC is performed on the signal by using the signal.