amp circuit

摘要

PURPOSE: An amplifier circuit is provided to increase the output of an amplifier in a miniaturized instrument by installing a first amplifier circuit and a second amplifier circuit. CONSTITUTION: An amplifier circuit includes a first amplifier circuit(100) and a second amplifier circuit(200). The first amplifier circuit includes an audio signal input unit and a first amplifier amplifying an audio signal in a ratio of input resistance and feedback resistance through the audio signal input unit. The second amplifier circuit includes a second amplifier which re-amplifies the audio signal amplified in the first amplifier circuit. The audio signal inputted through the audio signal input unit is amplified through the first amplifier circuit and the second amplifier circuit. The amplified signal is outputted through a speaker(300). The first amplifier circuit further includes a microphone signal input unit.