Mismatch shaping for a current-mode multibit delta-sigma DAC

Mismatch shaping allows the use of multibit quantization in delta-sigma ana log-to-digital converters and digital-to-analog converters (DAC's) since it noise-shapes the error caused by static element mismatch in a multibit DAC , In this paper, mismatch-shaping techniques for low-pass delta-sigma (Delt a Sigma) modulators are reviewed, and a mismatch-shaping technique For band pass Delta Sigma modulators is described. The dynamic error caused by frequ ent element switching is identified as a major source of error in a current -mode DAC with a continuous-time output. Modifying the mismatch-shaping alg orithm to account for this effect yields a continuous-time Delta Sigma DAC that is insensitive to both element mismatch and element switching dynamics . Experimental results confirm the effectiveness of the proposed techniques .