基于GaN功率集成电路的有源箝位反激电源

An Active Clamp Flyback Power Supply Based on GaN Power Integrated Circuit

随着人们对便携式电子产品充电速度要求不断提高和便携性能需求的提升,快速充电适配器行业正面临着越来越大的挑战。同时,在能源利用率被逐渐看重的今天,全球重要的规范机构对AC/DC外部电源制定了越来越严格的能效标准。而当今快充电源适配器主要存在体积过大、功率密度和充电效率较低的问题。首先,从拓扑入手详细阐述了有源箝位反激(ACF)变换器的工作原理。接着,针对功率密度的提高,以氮化镓(GaN)器件为应用背景,对比了两种不同方案的功率密度与效率,理论计算对比了上述两种应用方案的损耗。最后,制作了一台基于NV6117功率集成电路的49 cm^(3)(带壳)65 W的样机,在90 V AC满载效率可达92.8%,230 V AC满载效率可达94.7%,裸样机功率密度高达2.24 W/cm^(3),带壳功率密度达1.33 W/cm^(3)。

With the increasing demands for charging speed of portable electronic products and portable performance,the fast charging adapter industry is facing increasing challenges.At the same time,today when energy efficiency is gradually valued,important global regulatory agencies have established increasingly stringent energy efficiency standards for AC/DC external power supplies.However,today’s fast charging source adapters mainly have the problems of being too large,power density and low charging efficiency.First of all,this article explains in detail the working principle of the active clamp flyback(ACF)converter starting from the topology.Then,in view of the increase in power density,the power density and efficiency of the two different schemes are compared with the application background of gallium nitride(GaN)devices,and the loss of the above two application schemes are compared by theoretical calculation.Finally,a 49 cm^(3)(with shell)65 W prototype based on the NV6117 power integrated circuit is made.The efficiency at full load at 90 V AC can reach 92.8%,the efficiency at full load at 230 V AC can reach 94.7%,and power density of the bare prototype is as high as 2.24 W/cm^(3),with a shell power density of 1.33 W/cm^(3).