Low Power Consumption And High Power Density Integrated Dc-Dc Converter For Portable Equipments

We developed an integrated buck type DC-DC converter for portable electronic equipments. A newly developed pulse frequency modulation (PFM) control integrate circuits (ICs), which includes output power MOSFETs, achieved a low quiescent current below 14 mu A and small chip size of 1.4 x 1.1 mm(2) in 0.35 mu m CMOS process. The integrated converter consisted of the PFM control ICs on a planar inductor and had a maximum efficiency of 90% and a power density above 100 W/cm(3).