An oversampled multibit CMOS D/A converter for digital audio with 115-dB dynamic range

The analog part of a current-mode CMOS 5-b bidirectional digital/analog (D/A) converter for digital audio with 115-dB dynamic range and -90-dB distortion at 128-times oversampling is presented. The application of a multibit noise shaping approach combined with a sign-magnitude decoding in an oversampled D/A converter not only increases the dynamic range of the converter but also reduces the intermodulation sensitivity. A dynamic self-calibration technique is used to obtain the required relative accuracy and absolute linearity of the current sources. No laser or external trimming techniques are required.<
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