This book discusses one increasingly important issue in the VLSI design: low power. It covers the following topics: (a) basic concepts of low-power design, (b) low-power design methods and applications in industry chips, and (c) commercial CAD tools on low-power design. This book discusses the concepts, a set of known methods, industry cases and CAD tools on the low power design. It is organized in four chapters and a glossary is provided at the end of the book.