A 20-bit decimator IC for high-resolution audio A/D conversion

A decimator IC has been developed for use with noise-shaping front-end coders to implement a very-high-resolution A/D (analog-to-digital) converter intended primarily for professional audio applications. The IC contains a multirate filter structure to obtain a decimation ratio of 128:1 with 80 dB of stopband rejection. An input wordlength of 6 bits and an output wordlength of 20 bits allow signal-to-noise ratios in excess of 110 dB to be obtained with the appropriate front-end coder