| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital amplifying device capable of reducing noises when amplifying by a speaker after stably driving a FET. SOLUTION: A class D amplifier 100 comprises a modulator 103 for producing a modulation signal having a predetermined peak value after performing pulse width modulation about the acquired sound signal, a drive controlling means for controlling the peak value of the modulation signal after varying the peak value of the produced modulation signal, an amplifying circuit 200 having a FET(A) 201 and a FET(B) 202 and for amplifying the modulation signal while maintaining pulse waveform using the FET(A) 201 and the FET(B) 202, and a detecting circuit 104 for detecting temperature of the FET(A) 201 and the FET(B) 202 during driving. A drive controlling unit 300 is designed to control the peak value of the modulation signal based on the detected temperature of a voltage drive element, and to supply the modulation signal controlled its peak value to the FET(A) 201 and the FET(B) 202. COPYRIGHT: (C)2006,JPO&NCIPI
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