Abstract: A digital audio signal amplifier and a digital audio signal amplifying method provide safety and power efficiency by integrating a switching mode power supply and a digital audio amplifier into an apparatus. The digital audio amplifier includes a pulse modulation unit generate a pulse modulated audio signal by pulse-modulating an input audio signal, a switching unit to switch a DC voltage based on the pulse modulated audio signal, an insulation transformer to transform the output of the switching unit and to output the result of the transforming, and a low-pass filter to obtain an audio signal corresponding to the input audio signal by low-pass filtering the output of the insulation transformer, and to output the output audio signal. By integrating a switching mode power supply and a digital audio amplifier into an apparatus, the digital audio amplifier satisfies the insulation requirement and at the same time increases power efficiency.

Abstract: A digital audio system to store and reproduce a digital PWM signal and a method of processing an audio signal. The method includes; converting an audio source signal into a digital pulse width modulation (PWM) signal through a series of signal processing processes and storing the PWM signal in a separate storage medium, when an audio signal is reproduced, reading the digital PWM signal stored in the storage medium and decoding the signal into an analog PWM signal, and performing a power switching operation with the decoded analog PWM signal and extracting an audio signal.

Abstract: A digital audio signal amplifier and a digital audio signal amplifying method therefor are provided. More particularly, a digital audio signal amplifier in which both safety and power efficiency are achieved by integrating a switching mode power supply and a digital audio amplifier into one, and a digital audio signal amplifying method appropriate to the amplifier are provided. The digital audio amplifier includes: a pulse modulation unit generating a pulse modulated audio signal by pulse-modulating an input audio signal; a switching unit switching a DC voltage based on the pulse modulated audio signal; an insulation transformer transforming the output of the switching unit and outputting the result of the transforming; and a low-pass filter obtaining an audio signal corresponding to the input audio signal by low-pass filtering the output of the insulation transformer, and outputting the output audio signal.

Abstract: A digital audio system to store and reproduce a digital PWM signal and a method of processing an audio signal. The method includes; converting an audio source signal into a digital pulse width modulation (PWM) signal through a series of signal processing processes and storing the PWM signal in a separate storage medium, when an audio signal is reproduced, reading the digital PWM signal stored in the storage medium and decoding the signal into an analog PWM signal, and performing a power switching operation with the decoded analog PWM signal and extracting an audio signal.

Abstract: An apparatus and a method to limit a current by having different limiting references according to pulse widths of a current signal in an audio amplifier. The apparatus includes a pulse width modulator to generate a PWM signal by comparing an input audio signal and a reference signal, a power switching unit to switch a voltage source according to the PWM signal generated by the pulse width modulator, a current detector to detect a current signal flowing through a load by the voltage source supplied by the power switching unit, and a controller to apply different limiting values to different current levels according to pulse widths of the current signal detected by the current detector and to control the PWM signal generated by the pulse width modulator by comparing the applied limiting value to a current level value of the current signal detected by the current detector.