Sigma-delta ADC中数字滤波器设计

本文主要论述了用于音频系统ADC的过采样抽取滤波器的设计。系统讨论了滤波器的多级实现。采用了求平均值的方法去除1bit sigma-delta引入的直流电平。通过滤波器的多级化,左右声道共享组合电路,滤波采取时分复用思想,通过合理安排数字滤波器滤波执行时序以共享乘累加单元,有效地缩小了电路面积。

Design of a Digital Decimator in Sigma-delta ADC

Design of a digital decimator of sigma-delta ADC is discussed. This paper focuses the implement of multi-level filter. A novelty method of removing DC is used. By the methods of multi-level filter,left and right channel sharing combinational logic module and using TDMA in the sequential process of filters,the circuit area could be reduced observably.