A compact buck-converter using a thin-film inductor

We have developed a compact buck-converter using a thin-film inductor that is suitable for portable electronic equipment. The inductor consists of planar Cu coils and CoZrTa magnetic layers on a Si substrate; it is fabricated by a dry process. The converter is 3 mm thick and 10/spl times/6 mm in area; it operates at 1.6 MHz and has an efficiency of up to 85%.