Buck Regulator Boosts Efficiency At Low Currents

The MIC2204, a 2-MHz pulse-width-modulation buck regulator in a 3- by 3-mm MLF, uses a proprietary gate-drive scheme to achieve high efficiency at low currents. Operating from a 2.3- to 5.5-V input, the buck converter generates up to 600 mA of output at voltages as low as 1 V. The only external passives required are a small chip inductor and three ceramic capacitors. In converting a 5-V input to 3.3 V, the regulator can achieve efficiencies of 90% or more with loads as low as 50 mA. (See the Web-only figure, "MIC2204 Efficiency Versus Load.") A sync output function allows two or more devices to be daisy-chained in master-slave fashion for frequency matching. Pricing for the MSOP-10 version is $1.65 each in lots of 1000.

Micrel Semiconductor • www.micrel.com