Audio power amplifying apparatus and method

An audio power amplifying method performed by a b-th power amplifying terminal (1≦b≦B) of an audio power amplifying apparatus including the first through B-th power amplifying terminals, each of which power-amplifies an input alternating current (AC) audio input signal and outputs the power amplified result as an audio output signal, the method comprising:

• dividing the audio input signal into positive and negative portions and to preamplify the positive and negative portions and to obtain the amplified positive and negative portions;
• selecting one of first through M-th positive supply voltages having a level proportional to a level of the preamplified positive portion;
• selecting one of first through M-th negative supply voltages having a level proportional to a level of the preamplified negative portion;
• amplifying the preamplified positive and negative portions using the selected one of the positive and negative supply voltages, respectively;
• and
• combining the amplified positive and negative portions to produce the audio output signal.

A power amplifying apparatus to amplify an input signal to be output as an amplified signal, comprising:

• a splitting unit that splits the input signal into signal portions;
• a power supply to supply voltages;
• an amplifier to match ones of the signal portions with corresponding ones of the supply voltages and to amplify the signal portions using the corresponding supply voltages;
• and
• a signal synthesizer to receive the amplified signal portions and to combine the amplified signal portions as the amplified signal.

A power amplifying apparatus to amplify an input signal to be output as amplified signals to different devices, comprising:

• an input terminal to receive the input signal;
• and
• power amplifying terminals to receive the input signal from said input terminal and to output amplified signals to the different devices,
• wherein each said power amplifying terminal comprises
• a splitting unit that splits the input signal into signal portions,
• a power supply to supply voltages,
• an amplifier to match ones of the signal portions with corresponding ones of the supply voltages and to amplify the signal portions using the corresponding supply voltages, and
• a signal synthesizer to receive the amplified signal portions and to combine the amplified signal portions as the amplified signal to be output to the corresponding one of the different devices.

A power amplifying method comprising:

• dividing an input signal into signal portions;
• selecting a first supply voltage from a plurality of supply voltages such that the first supply voltage has a level proportional to a level of a first signal portion of the signal portions;
• selecting a second supply voltage other than the first supply voltage from the plurality of supply voltages such that the second supply voltage has a level proportional to a level of a second signal portion of the signal portions;
• amplifying the first signal portion using the selected first supply voltage;
• amplifying the second signal portion using the selected second supply voltage;
• and
• combining the amplified first and second signal portions to produce the output signal.

A power amplifying apparatus to amplify an input signal to be output as an amplified signal, comprising:

• a power supply to supply voltages of different levels;
• and
• an amplifier that linearly selects one of the supply voltages having a level proportional to a level of the input signal and to amplify the input signal using the selected one of the supply voltages to be output as the amplified signal,
• wherein said amplifier selects the one of the supply voltages without using a comparator.