The LTC3101 is a complete power management solution for low power portable devices. It provides three high efficiency switching DC/DC converters which seamlessly transition from battery to USB/wall adapter power when available. A synchronous buck-boost regulator provides complete flexibility, allowing operation from a single Li-Ion/Polymer battery, 2 to 3 AA cells, a USB port or any other power source operating from 1.8V to 5.5V.