| 摘要 |
PROBLEM TO BE SOLVED: To protect an output element by enhancing distortion performance in a pulse width modulation amplifier. SOLUTION: The pulse width modulation amplifier comprises a mean for pulse width modulating an audio signal, a capacitor for removing DC component in the waveform of a pulse width modulation signal being output from the pulse width modulating means, a means for comparing the amplitude of a pulse width modulation signal being outputte from the capacitor with a threshold and adjusting the rising time and falling time of the waveform of a pulse width modulation signal by bringing the voltage of a pulse width modulation signal lower than the threshold to 0 and bringing the voltage of a pulse width modulation signal not lower than the threshold to a constant level, a means for amplifying the pulse width modulation signal being outputted from the rising/falling adjusting means, a means for detecting a current flowing through the amplifying means, and a means for controlling the threshold of the rising/falling adjusting means based on a current detected by the current detecting means. COPYRIGHT: (C)2006,JPO&NCIPI
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