| 摘要 |
PROBLEM TO BE SOLVED: To prevent pop noise from being generated with a relatively simple and compact circuit configuration and control timing. SOLUTION: A D/A converter 20 converts a digital audio signal into an analog audio signal and, at the same time, a non-inverting amplifier 30 amplifies the analog audio signal. An output signal from the non-inverting amplifier 30 is amplified by inverting amplifiers 40, 50 of two stages with first timing and an output signal from the inverting amplifier 50 is input to a speaker amplifier 60 by a switch 75. The output signal of the inverting amplifier 50 is output to a speaker 83 with second timing subsequent to the first timing, and the output signal of the inverting amplifier 50 is amplified by the speaker amplifier 60 and output to the speaker 83. With third timing subsequent to the second timing, the output of each of the inverting amplifiers 40, 50 is stopped and the output of the speaker amplifier 60 is stopped. COPYRIGHT: (C)2009,JPO&INPIT
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