Patent ID: 7579908

Claim:
An electronic system that includes a digital audio amplifier comprising: a continuous time modulator adapted to generate a difference signal between an audio bitstream and a feedback signal, and to perform a modulation process on the difference signal to generate an input pulse modulated signal; a class D output stage adapted to receive, quantize, and amplify the input pulse modulated signal to generate an output pulse modulated signal; an additional output stage selected from a group of output stages consisting of a class B output stage and a class AB output stage, wherein the additional output stage is adapted to receive the input pulse modulated signal and to generate an analog output signal; and a feedback path, electrically coupled between the class D output stage and the continuous time modulator and between the additional output stage and the continuous time modulator, and adapted to provide the output pulse modulated signal or the analog output signal as the feedback signal to the continuous time modulator.