| 摘要 |
PURPOSE:To obtain a sound output waveform with remarkably reduced crossover distortion by decreasing sufficiently an idle current at steady-state where no sound is outputted while increasing the idle current at driving where the sound is outputted. CONSTITUTION:An F is a circuit detecting a peak of an output signal of signal output circuit E given via a transistor T9 and is provided with a resistor R6 having a low resistance value, a resistor R7 having a high resistance value and a charge/discharge capacitor C3. A G is a circuit giving an idle current deciding signal to an idle current diciding circuit C in response to an output of the peak detecting circuit F. When a signal is given to a speaker via an output terminal OUT, the amplitude of the level of the signal by the peak detecting circuit F and the idle current (i) is decided in response to this detected output. Thus, since the idle current (i) is also increased with a large sound output, the sound output waveform with reduced crossover distortion is obtained and the idle current (i) does not almost flow at no sound. |
