| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce click noise in a sound output device by a simple configuration. Ž<P>SOLUTION: When the power supply of the sound output device 10 is turned on, an input signal S_in is inputted and a mute signal S_m is turned on, a first driver 14 is turned off and an amplifier circuit 20 is not driven. On the other hand, a second drive 52 is turned on, so that a switching control circuit 60 is driven and an output capacitor 40 is charged through a noise reduction resistor 70. When the mute signal S_m is turned on, the time constant and degree of an integrator group constituting a pulse modulation part 12 are changed and the feedback operation of the sound output device 10 is maintained in a stable state. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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