2023 年 7 巻 1 号 p. 80-84
In recent years, point-of-load DC-DC converters, which have a low voltage and large current output for DC power delivery to CPUs and GPUs, are required to have a smaller and smaller footprint for power-saving management using a power delivery scheme with a large number of small granular converters. A converter using a double-current rectifier circuit has been proposed for use as a high to low voltage/large current step-down converter. The double-current rectifier circuit rectifies the output voltage by half and the output current by twice and is advantageous for low-voltage and high-current driving. However, the double-current rectifier circuit requires a coupled inductor. In this study, for a beyond-10-MHz LLC resonant DC-DC converter with a double-current rectifier circuit, the influence of the coupled inductor on LLC resonant operation was investigated, and a prototype coupled inductor was fabricated and evaluated. The prototype inductor, which used PCB-based straight-line conductors and Fe-based metal composite magnetic cores, exhibited a magnetizing inductance of 32.3 nH and a coupling coefficient of 0.98 at 15 MHz, and these properties were considered to be sufficient for the converter under investigation.
