New trends toward high-efficiency portable power and audio

摘要

Consumers of portable wireless applications continue to demand more and more features such as digital still camera functions, hands-free talk mode and stereo audio for surround-sound effects, not to mention additional wireless connectivity enabled through Bluetooth and 802.11 Wireless LAN technology. As form factors decrease in size, batteries are prohibited from becoming larger. To compensate for the increased power requirements, design engineers must look for new ways to decrease overall system power consumption. One simple solution is to move from linear power regulation to switch-mode dc/dc conversion and Class-D audio power amplifiers instead of traditional Class-AB amplifiers. The switch can significantly contribute to higher power-efficiency.