A GaN and Si Hybrid Solution for 48V-12V Automotive DC-DC Application

A high efficiency and low-cost 48V-12V buck converter with a GaN/Si hybrid solution for automotive applications is discussed in this paper. The hybrid approach has lower system losses versus the pure Si solution, and has similar efficiency but lower cost as compared to the pure GaN solution. An ultra-low parasitics switching energy measurement platform for the 100V switches is designed to evaluate the switching performance of the GaN/Si hybrid approach. A cost-effective gate driving circuit for the hybrid solution is discussed. A detailed loss comparison of the hybrid, pure GaN and pure Si solutions is made. The advantages of the hybrid solution are experimentally verified.