| 摘要 |
PROBLEM TO BE SOLVED: To perform high-resolution reproduction of a high-frequency component and a high-efficient reproduction of a low-frequency component, and reduce cross modulation noise generated by a difference of sampling frequencies in a PWM (pulse width modulation) amplifier which performs pulse width modulation of an input analog voice signal and power amplification. SOLUTION: A voice amplification device comprises a pulse oscillator 17 which generates and outputs a clock pulse; a frequency divider 18 which divides output of the pulse oscillator; a high frequency pulse width modulation amplifier which receives output of the pulse oscillator as a clock pulse, extracts the high-frequency component from the voice signal, applies pulse width modulation, and performs power amplification; and a low-frequency pulse width modulation amplifier which receives the output of the frequency divider as a clock signal, extracts the low-frequency component from the voice signal, applies pulse width modulation, and performs power amplification. COPYRIGHT: (C)2007,JPO&INPIT
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