| 摘要 |
PROBLEM TO BE SOLVED: To provide a PWM modulation device and an audio signal output device to which the PWM modulation device is applied, capable of reducing a rush current at start-up of a PWM output.SOLUTION: PWM modulation device 180P includes; a start-up control circuit 22 for generating and outputting a control signal CS, a start-up flag signal FLG, and a selection indication signal SEL, according to a count value of a counter 24; a PWM modulator 20 for start-up, for generating and outputting a PWM output signal for start-up, according to an input control signal; a PWM modulator 18 for generating a PWM output signal from a signal supplied from an external device, according to an input start-up flag signal, and outputting the PWM output signal; and a selector 32 for selecting either the PWM output signal for start-up from the PWM modulator for start-up or the PWM output signal from the PWM modulator, according to an input selection indication signal, and outputting the selected signal to a driver output stage 40P.SELECTED DRAWING: Figure 5 |
