A High Density 400 W DC/DC Power Module with Integrated Planar Transformer and Half Bridge GaN IC

The increasing popularity of gaming laptops, portable workstations, all-in-one computers, smart displays, and large screen OLED TVs has led to a rising demand for high-efficiency, high-density power supplies in the range of 300 W-500 W. Especially the all-in-one computer, smart display, and the large screen OLED TVs, they face form factor limitations, posing challenges for the overall thickness of the power supply. In this paper, an LLC resonant converter module is designed as the DC/DC stage of the power supply. By utilizing a highly integrated half bridge GaN power IC, the switching frequency of the DC/DC stage is boosted to over 500 kHz, enabling the design of a PCB-based transformer with an integrated resonant inductor. The prototype has a profile of only 8 mm, attains 21.5 kW/L power density (62.5 x 37.2 x 8 mm), which is far beyond the state-of-the-art design [1] - [3], with a peak efficiency of 98.1% and a full load (400 W) efficiency of 97.4%.