High-Order Mismatch-Shaping in Multibit DACs

This brief reports a high-order mismatch-shaping technique for multibit ΔΣ digital-to-analog converters (DACs). It builds upon the vector-based method but with two key improvements. First, a new vector quantization (VQ) scheme exploits the information in all vector variables. This VQ scheme allows the second-order mismatch shaping for large input signals and makes possible the stable third- and fourth-order mismatch shaping. Second, a hardware-efficient method maintains the average of the vector variables bounded. Simulations under various conditions prove its validity.