A versatile, efficient digital filter for decimation and interpolation

Abstract

The area and power consumption of oversampled data converters are governed largely by the associated digital decimation and interpolation filters. This paper presents an area- and power-efficient programmable digital filter for decimation and interpolation in digital-audio applications. Several architectural and implementation features reduce the complexity of the filter and allow its implementation in a die area of only 3670 mils/sup 2/ (2.37 mm/sup 2/). The filter is first described in the context of decimation for an oversampled A/D converter employing a second-order sigma-delta modulator. Extensions of the filter to accommodate other modulators, as well as to perform interpolation for oversampled D/A conversion, are then discussed.