摘要 |
There is provided an audio amplifier circuit (200), comprising: an input, for receiving an input signal; an amplifier (205) for receiving a modified input signal and outputting an amplified signal; and a feedback loop (245) comprising digital circuitry for feeding back the amplified signal and combining a feedback signal with the input signal to generate the modified input signal. The feedback loop (245) comprises: a low-pass filter (220) for filtering the amplified signal; a comparator (225) for comparing the filtered signal with a threshold value and outputting a comparison signal; and an integrator (230) for integrating the comparison signal and outputting the feedback signal. According to another embodiment, the feedback loop comprises an integrator and a sigma-delta modulator. |