Higher order interpolative analog to digital converters

Design of the basic interpolative A/D converter was explored. Improving performance by replacing the simple direct feedback quantizer by some more general quantizer structure, and then replacing the digital filter by a new filter optimized for this new quantizer was emphasized. It is shown that there are certain practical considerations, namely stability and quantizer overload, which make higher order interpolative converters increasingly difficult to implement. It is concluded that in most cases it will be impractical to extend the higher order interpolation technique beyond the fourth order.