News From: http://www2.electronicproducts.com/4-A_buck-boost_converter_provides_96__efficiency-article-hlpo02_jun2010-html.aspx

The TPS63020 PMIC is the industry’s smallest and highest-performance buck-boost converter to feature a 4-A switch and up to 96% efficiency. It helps extend battery life in smartphones, portable medical equipment, DLP pico projectors, and other battery-powered multimedia devices.

The buck-boost device operates with a wide input voltage range of 1.8 to 5.5 V and can discharge lithium batteries down to 2.5 V. The single-inductor, 2.4-MHz converter comes in a 3 x 4 x 1-mm package, is 60% smaller than competitive versions. It generates 3 A at 3.3 V in step-down mode and more than 2.0 A at 3.3 V in boost mode. The converter supports one-cell lithium-based or 2- or 3-cell alkaline, NiCd, or NiMH batteries. ($2.50 ea/1,000 — available now.)