Development of Oversampling Sigma-Delta Modulators with Nouniform Multibit Quantizer

비균일 양자기에 의한 과표본화율의 멀티빗트 시그마-델타 변조기의 개발

We have proposed a new structure of the multibit ovesampling sigma-delta modulator. To solve the problkem of requring the accurate precision of the analog components, the novel digital correction scheme with a ROM-table has been employed to enhance the SNR for the proposed system. This architecture has good features compared with the 1-bit approach, including significantly lower quantisation noise for a given oversampling ratio, as well as improve dstability characteristics. Then we hve shown the validity of the proposed system by use of the software developed for the performance evaluation and by realizing the system with SCFs(switched capacitor filters).