A 2MHz, 97.4% Peak Efficiency, Heterogenous GaN/BCD 48-to-12 V Cascaded Switched Capacitor Converter With ZVS Auxiliary Technique

It has been demonstrated that switched capacitor (SC) converters have the potential to achieve higher efficiency and higher power density than magnetic-based converter. With two conventiona12-to-1 SC converters cascaded, this article presents a 2MHz, 12-54V input intermediate bus converter (IBC) mainly to realize the typical use of 48-to-12 V (fixed 4:1 step-down ratio) for hybrid electrical vehicle and other modern advanced industry. Based on tridimensional heterogeneous integration (3D-HI) of gallium nitride (GaN) and bipolar-CMOS-double-diffused meta-loxide-semiconductor (DMOS) (BCD) technology, the novel driving strategy and zero voltage switching (ZVS) auxiliary technique suggested in this work, the proposed highly-integrated cascade SC converter sized $3.74\times 3.09$ mm ² achieves one of the best overall metrics among the state of the arts. Verified through post-simulation, it features a peak efficiency of 97.4% and power density of 1.87 W/mm ² .