Nyquist-Rate Current-Steering Digital-to-Analog Converters With Random Multiple Data-Weighted Averaging Technique and Q^NRotated Walk Switching Scheme

In this brief, Nyquist-rate current-steering digital-to-analog converters (DACs) applying the random multiple data-weighted averaging (RMDWA) technique and the Q^Nrotated walk switching scheme are proposed such that high spurious-free dynamic range (SFDR) and small maximum output error can be achieved without calibrations, which are area and power consuming. RMDWA suppresses the harmonics caused by element mismatches to gain high SFDR performance. Furthermore, Q^Nrotated walk can lower the maximum output error when RMDWA and Q^Nrotated walk are employed simultaneously. Because the benefits of both dynamic element matching technique and switching scheme are obtained by the proposed DAC structure, the proposed structure can deliver smaller maximum output errors than traditional randomization techniques even if a low-cost small-area DAC with poor matching property is adopted.