A Pre-Charge Tracking Technique in the 40 MHz High-Speed Switching 48-to-5 V GaN-Based DC–DC Buck Converter for Reducing Large Self-Commutation Loss and Achieving a High Efficiency of 95.4%

Abstract

For automobile applications, a high-speed switching 48-to-5 V dc&#x2013;dc buck converter is implemented in the 0.5-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> CMOS and 0.5-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> gallium nitride (GaN)-on-Si processes. This proposed converter includes a pre-charge tracking technique, a temperature-dependent controlled gate driver, and an adaptive relaxation gate drive control technique. The measurement results of this article show that the efficiency can be increased by about 10.3&#x0025; and can ensure the driving current capacity of enhance GaN (E-GaN). The built-in local negative feedback loop improves the reliability and reduces <inline-formula> <tex-math notation="LaTeX">$R_{\mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> by 21&#x0025; to reach the peak efficiency as high as 95.4&#x0025;.