抄録
When sigma-delta digital to analogue converter that has multi bit DAC is used, because of the mismatches of elements in output DAC, the non-linearity occur to output. And non-linearity lower S/N and the accuracy of conversion go bad. These mismatches occur at manufacturing process, so we cannot avoid the non-linearity as far as we use multi bit DAC. Then “The Dynamic Element Matching” technique is proposed as a means to ease this deterioration. In order to ease the deterioration of accuracy, I propose digital trimming method using a Double DWA as ⊿∑ D/A converter.
This paper shows that we can improve S/N about 10dB with the proposed technique (Double DWA and digital trimming) compared with conventional DWA, on the simulation.
