Book excerpt: The book gives an overview of the state-of-the-art in SigmaDelta design and of the challenges for future realizations. It provides an understanding of the fundamental power efficiency of SigmaDelta converters. In addition, it presents an analysis of the power consumption in the decimation filter. Understanding these power/performance trade-offs, it becomes clear that straight-forward digitization of a conditioning channel, i.e. exchanging analog for digital conditioning, comes at a major power penalty.