The LM3671 step-down DC-DC converter is optimized for powering low voltage circuits from a single Li-Ion battery and input voltage rails from 2.7V to 5.5V. It provides up to 600mA load current, over the entire input voltage range. There are several different fixed voltage output options available as well as an adjustable output voltage version range from 1.1V to 3.3V.
The LM3677 evaluation board is a working demonstration of a step down DC-DC converter. This application note contains information about the evaluation board. For further information on buck converter topology, device electrical characteristics, and component selection, please refer to the datasheet.