Recently, various multibit noise-shaping digital-toanalog converters (DAC's) have been proposed that use digital signal processing techniques to cause the DAC noise arising from analog component mismatches to be spectrally shaped. Such DAC's have the potential to significantly increase the present precision limits of 16 data converters by eliminating the need for one-bit quantization in delta-sigma modulators. This paper extends the practicality of the noise-shaping DAC approach by presenting a general noise-shaping DAC architecture along with two special-case configurations that achieve first- and second-order noise-shaping, respectively. The second-order DAC configuration, in particular, is the least complex of those currently known to the author. Additionally, the paper provides a rigorous explanation of the apparent paradox of how the DAC noise can be spectrally shaped even though the sources of the DAC noise---the errors introduced by the analog circuitry---are not known to the ...

A second-order audio analog-to-digital converter (ADC) 16 modulator using a second-order 33-level tree-structured mismatch-shaping digital-to-analog converter (DAC) is presented. Key logic simplifications in the design of the mismatch -shaping DAC encoder are shown which yield the lowest complexity second-order mismatch-shaping DAC known to the authors. The phenomenon of signal-dependent DAC noise modulation in mismatch-shaping DACs is illustrated, and a modified second-order input-layer switching block is presented which reduces inband DAC noise modulation by 6 dB. Implementation details and measured performance of the 3.3-V 0.5- m single-poly CMOS prototype are presented. All 12 prototype devices achieve better than 100-dB signal-to-noise-and-distortion and 102-dB dynamic range over a 10--20 kHz measurement bandwidth. Index Terms---analog--digital conversion, CMOS analog integrated circuits, delta--sigma modulation, digital--analog conversion, dynamic element matching, mixed analog--digital integrated circuits. I.