USB Port-Powered Li-Ion/Li-Polymer Battery Charging

The Universal Serial Bus (USB) allows many computer peripherals to be easily swapped without having to turn off the computer. Today, a variety of handheld, battery-operated peripherals provide USB ports to facilitate data transfer to and from a host computer. With the introduction of the new USB 2.0 specification, CD/DVD players, MP3 players, cameras, personal data assistants and even cell phones can transfer data at rates up to 480 Mbps. These peripherals are, in some instances, self-powered. As a result, many of these peripherals do not take full advantage of the USB port. Often overshadowed by the data interface is the power capability that a USB port provides. Microchip's MCP73853/55 and MCP73861 advanced, fully-integrated, single-cell Li-Ion/Li-Polymer charge-management devices allow these peripherals to utilize the full power of the USB port.

This application note describes how, with the MCP73853/55, harnessing the power of the USB port for battery charging becomes extremely simple.