Design and Analysis of High Efficiency Line Drivers for x DSL covers the most important building block of an x DSL (ADSL, VDSL, …) system: the line driver. Traditional Class AB line drivers consume more than 70% of the total power budget of state-of-the-art ADSL modems. This book describes the main difficulties in designing line drivers for x DSL. The most important specifications are elaborated staring from the main properties of the channel and the signal properties. The traditional (class AB), state-of-the-art (class G) and future technologies (class K) are discussed.The main part of Design and Analysis of High Efficiency Line Drivers for x DSL describes the design of a novel architecture: the Self-Oscillating Power Amplifier or SOPA.