| 摘要 |
Techniques for performing SigmaDelta modulation with offset in order to reduce out-of-band quantization noise are described. In an exemplary oversampling DAC that implements SigmaDelta modulation with offset, an interpolation filter performs upsampling and interpolation filtering on data samples to generate input samples. A summer adds an offset to the input samples to generate intermediate samples. The offset alters the characteristics of the quantization noise from a SigmaDelta modulator and may be selected to obtain the desired quantization noise characteristics, to retain as much dynamic range as possible, and to simplify the removal of the offset. The SigmaDelta modulator performs upsampling and noise shaping on the intermediate samples and provides output samples. An offset removal unit removes at least a portion of the offset from the output samples in the digital or analog domain. A DAC converts the output samples to analog.
|
