| 摘要 |
PURPOSE: A mobile communication terminal comprising an automatic volume control device is provided to automatically control the volume of a sound source signal which exceeds a reference level, thereby maintaining an optimal sound state regardless of the level of the sound source signal. CONSTITUTION: A peak sensing circuit(40) is used, wherein one end thereof is connected between a CODEC(33) and an amplifier(35) to decide a level of an input current while other end is connected to an MSM(30) to control volume in accordance with each level. If a sound source signal exceeding a reference level is inputted, a diode of the peak sensing circuit(40) is connected between the CODEC(33) and the amplifier(35) in forward way while a current sensor is connected to the diode to measure a current level. A bias resistor is connected between the diode and the current sensor to control a current value inputted to the current sensor. The MSM(30) controls volume according to the measured current value.
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