Recent requirements for voltage regulators in mobile apparatus have included small size, thinness and low power dissipation. We have developed a new dc-dc converter module which includes a microinductor using CoFeSiB/SiO2 multilayer film and a control IC with dimensions of 6.0 × 6.0 × 1.0 mm3. Characteristics are an input voltage from 3.0 V to 5.0 V and an output voltage from 0.8 V to 4.8 V. This converter module has achieved a maximum efficiency of about 92% and 70% at output voltages of 2.0 V and 0.8 V, respectively.
