| 摘要 |
PURPOSE: A class-D amplifier is provided to use an integrator, an attenuation command pulse generating unit, and an attenuation unit to control a mute function, thereby preventing increases of a circuit size and control complexity. CONSTITUTION: An output limit command generating unit(310) outputs output limit command signals by detecting a digital signal out of a limited range. An attenuation command pulse generating unit(320) includes an integrator for integrating the output limit command signals. The attenuation command pulse generating unit outputs an attenuation command pulse with a pulse width corresponding to an integrated value. An attenuation unit is installed on an input route of an input signal. The attenuation unit attenuates the input signal based on the attenuation command pulse. A mute function controller(330) controls the integrated value without respect to the output limit command signal. The mute function controller controls an attenuation amount of the attenuation unit applied to the input signal.
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