AUTOMATIC GAIN CONTROL CIRCUIT

摘要

An automatic gain control circuit comprising an input terminal means for receiving first and second signals, an amplifier for receiving and amplifying first and second signals and outputting a first output signal when receives the first signal and outputting a second output signal when receives the second signals, input means for receiving an operation control signal and responsive to the operation control signal for separately inputting the first and second signals to the amplifier with a predetermined interval of time, control signal generating means responsive to the second output signal of the amplifier for generating a control signal, selection means connected to the input means for supplying the second output signal of the amplifier to the control signal generating means when the second signal is fed to the amplifier and sending out the first output signals to an external circuit when the first signal is fed to the amplifier and gain control means connected to the amplifier and the control signal generating means and responsive to the control signal for regulating the gain of the amplifier, wherein the control signal generating means includes gain maintaining means for maintaining the regulated gain of the amplifier.