| 摘要 |
PROBLEM TO BE SOLVED: To provide a class D amplifier with a high efficiency in which the distortion of an output signal resulting from the fluctuation of a power supply voltage fed to a power switching means is drastically reduced in comparison with in the conventional practice and which can be used without trouble even though the power supply voltage changes in a comparatively wide range. SOLUTION: This class D amplifier is characterised by being provided with a switching means 4 for switching the power supply voltage according to an input signal subjected to pulsewidth modulation, a feedback correcting means 5 for correcting the pulsewidth of an input signal supplied to the switching means in accordance with the amplitude of an output signal of the switching means, a reference signal generating means 11 for generating a level reference signal from the power supply voltage, and a level adjusting means 2 for adjusting the amplitude of an input signal which is supplied to the feedback correcting means and is subjected to pulsewidth modulation in accordance with the value of the level reference signal. COPYRIGHT: (C)2004,JPO&NCIPI
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