An Ultra-High Efficiency High Power Density 140W PD3.1 AC-DC Adapter Using GaN Power ICs

With ever increasing demands of smaller size, lighter weight for all forms of consumer electronics, efficient power conversion has always been pursued rigorously. This paper demonstrates an ultra-high efficiency and high power density design of power factor correction (PFC) and asymmetrical half-bridge (AHB) Flyback converter for adapter application. The design procedures, including the optimization of PFC output voltage, AHB flyback transformer, and synchronous rectifier power supply circuit, are presented in detail. A 140W PD3.1 prototype is developed to verify the feasibility of the system design. The prototype achieves 94.5% efficiency at 90Vac and 95.8% at 230Vac which is 1∼2% higher than the state of art product. The power density (exclude case) is more than 35W/in3.