Audio processing circuit whose output stage has different configuration based on signal strength

An audio processing circuit, comprising:

• a digital signal processing circuit, configured to process a digital audio signal to generate a processed signal;
• a digital modulation circuit, configured to generate a modulated signal according to the processed signal;
• an output stage, configured to generate an output audio signal according to the modulated signal;
• a voltage regulator, configured to receive a supply voltage and suppress and attenuate power noise in the supply voltage to generate a regulated supply voltage;
• and
• a signal detection circuit, configured to detect a signal strength of the digital audio signal and/or the processed signal to generate a first control signal to control the output stage to use the supply voltage or the regulated supply voltage to generate the output audio signal;
• wherein when the signal detection circuit detects the signal strength of the digital audio signal and/or the processed signal, and the signal detection circuit determines that the digital audio signal and/or the processed signal is a small signal, the signal detection circuit generates the first control signal to control the output stage to use the regulated supply voltage, without using the supply voltage;
• and when the signal detection circuit determines that the digital audio signal and/or the processed signal is a large signal, the signal detection circuit generates the first control signal to control the output stage to use the supply voltage, without using the regulated supply voltage.