High Power Density Integrated Transformer With Quasi All-in-One Structure for LLC DCX

The magnetic integration technology is useful to improve the power density of LLC DC transformer (DCX) converter. A high-power density integrated transformer with quasi all-in-one structure is proposed in the letter, which can integrate almost all components within the winding area, including primary power devices, synchronous rectification mosfets, output capacitors, resonant capacitors, drivers, and controller. The footprint of converter is reduced by this integration method, and the power density is improved accordingly. The proposed integration method can be realized through a novel winding structure. The design details are illustrated, which is then verified by a 1.4 MHz 48 V-6 V 300 W prototype. The experimental results show the power density of 2840 W/in3 and the peak efficiency of 97.3%. The proposed integration method has advantages in applications with limited space.