Description

This application report discusses digital filters which are a ubiquitous feature in delta-sigma analog to digital converters (ADCs). Digital low-pass filters are essential to the functionality of a delta-sigma ADC, which relies on oversampling and noise shaping to push quantization noise out of band. There are variations between the types of digital filters used in delta-sigma ADCs that provide various benefits and drawbacks that orient them to different applications. The types of filters and the tradeoffs between them are discussed in this report.