Patent ID: 7315264

Claim:
A multi-bit digital noise shaper comprising: a noise shaper quantizer configured to quantize an input digital audio signal and to produce an output digital audio signal, and clip the output digital audio signal when the input digital audio signal exceeds a threshold value; and a filter coupled to the noise shaper quantizer and configured to filter a difference between the input digital audio signal and the output digital audio signal and to add the filtered difference to the input digital audio signal, wherein the noise shaper is configured to inhibit undesirable transient response in the output digital audio signal when the noise shaper quantizer stops clipping the output digital audio signal by enabling an internal state of the noise shaper to vary within a first range of values when the noise shaper quantizer is not clipping an input signal, and enabling the internal state of the noise shaper to vary within a second range of values when the noise shaper quantizer is clipping the input signal.