Patent ID: 7508873
Filing Date: 2009-03-24
Classification: H03F

Abstract:
1. A pulse width modulator for use in a digital amplifier, comprising: a pop noise reducer for reducing pop noise by controlling a width and a phase of a pulse of a pulse width modulation (PWM) signal output from the pulse width modulator, wherein the pop noise reducer includes: a PWM pulse register for storing a width and a phase values of a pulse of the PWM signal; and a pulse generator for outputting the PWM signal according to the values stored in the PWM pulse register wherein a PWM amplifier of one of a PN half bridge type and a PN full bridge type using both a P channel MOSFET and an N channel MOSFET is connected to an output port of the pulse width modulator and the pop noise reducer gradually increases the pulse width of the PWM signal over at least two pulses when power is applied to the digital amplifier.