This chapter provides a review of system-level and circuit-level implementation aspects of strategic adaptive power management techniques which require wideband efficient power amplification, and that are crucial for power demanding loads in portable devices, such as envelope tracking for polar RF power transmitters, and on-chip line drivers for power line communications. The stringent specifications of such amplifiers pose relevant challenges both to assess the system-level impact of the amplifier limitations, as well as to design the power converter both in terms of converter topology and control. A discussion on advanced topologies aiming miniaturization and wideband low-distortion operation, both multi-level conversion and linear-assisted scheme, is presented. Details of advanced modulation and control methods are shown, namely low-oversampling ratio sigma-delta modulation with high-order filter, and digital predistortion of output filter dynamics built-in in PWM modulation.