The LTC3455 is a complete power management solution for a variety of portable applications. The device contains two synchronous step-down DC/DC converters, a USB power controller, a full-featured Li-Ion battery charger, a Hot Swap output, a low-battery indicator, and numerous internal protection features. The LTC3455 provides a small, simple solution for obtaining power from three different power sources: a single-cell Li-Ion battery, a USB port, and a wall adapter. Current drawn from the USB bus is accurately limited under all conditions. Whenever a USB or a wall adapter is present, the battery charger is enabled and all internal power for the device is drawn from the appropriate external power source. All outputs are discharged to ground during shutdown to provide complete output disconnect. The device is available in a 4mm x 4mm 24-pin exposed-pad QFN package.