Dealing with Power Management Requirements in Ultraportable Devices

A new breed of extremely small electronic products promises to extend the digital lifestyle into entirely new domains. Ranging from Bluetooth® wireless headsets and handheld GPS devices to tiny MP3 players and utility watches, these new ultraportable devices allow users to take their communication links, data, music, and video farther than ever before. Optimized for on-the-go use and powered by single-cell Lithium-Ion (Li-Ion) batteries, these tiny devices set new standards for packing high levels of functionality into small packages. While this equipment category opens up new applications for today's product development teams, it also brings a new set of challenges for power management. Core processors demand sources to supply power with high efficiencies under varied load conditions. RF and audio circuits require power management systems that deliver low noise and high isolation while maintaining high power efficiency requirements inherent in small ultraportable systems. Battery charging circuits must be capable of automatically adapting to changing conditions coming from USB ports and line-supplied power adapters or 'wall warts.” Displays vary in type and purpose, yet require highly flexible and efficient power conversion. This article examines how evolutionary changes in power management IC design are helping designers meet these new requirements.