一种应用于48V-1V系统的隔离型混合模式降压变换器  

An Isolated Hybrid Buck Converter Applied to 48 V-1 V Systems

作　　者：谢泽亚 甄少伟[1] 杨芮 赵冰清 熊海亮 周春华[1] 罗萍[1,2] 张波 XIE Zeya;ZHEN Shaowei;YANG Rui;ZHAO Bingqing;XIONG Hailiang;ZHOU Chunhua;LUO Ping;ZHANG Bo(State Key Lab.of Elec.Thin Films andIntegr.Dev.,Univ.of Elec.Sci.and Technol.of China,Chengdu 610054,P.R.China;Institute of Elec.and Inform.Engineer.of UESTC in Guangdong,Dongguan,Guangdong523808,P.R.China)

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054 [2]电子科技大学广东电子信息工程研究院,广东东莞523808

出　　处：《微电子学》2022年第5期803-809,共7页Microelectronics

基　　金：广东省基础与应用基础研究基金资助项目(2021A1515011309)。

摘　　要：提出了一种应用于48 V-1 V系统的隔离型混合模式降压变换器,利用飞电容和变压器实现高转换比应用下的高转换效率。混合变换器结合了开关电容变换器和开关电感变换器,其中飞电容承担了部分电压降,实现了功率开关管电压应力的降低。由于开关节点处的电压摆幅较小,开关损耗随之减小;通过使用更低压的功率开关管,实现功率开关管导通损耗减小。在此基础上,隔离型混合模式降压变换器通过时序控制可以实现软开关,进而实现功率开关管开关损耗减小,使得整体效率提升。在隔离型混合模式降压变换器中,飞电容还具有隔直电容的作用,可以防止变压器偏磁。在典型应用下,即在48 V输入电压、1 V输出电压、500 kHz开关频率下,峰值效率为94.84%。An isolated hybrid buck converter for 48 V-1 V system is proposed, utilizing the flying capacitor and transformer to achieve high conversion efficiency in high conversion ratio applications. The hybrid converter combines the switched capacitor converter and the switched inductor converter, in which the flying capacitor is charged with part of the voltage drop to reduce the voltage stress of the power MOS. Since the voltage swing at the switch node is smaller, the switching loss is reduced accordingly. By using lower voltage power MOS, the conduction loss is reduced. Moreover, the isolated hybrid buck converter can achieve soft-switching through timing control, thereby reducing the switching loss of the power MOS, and making the overall efficiency higher. In the isolated hybrid buck converter, the flying capacitor has the function of the DC-blocking capacitor, which can prevent the magnetic bias of transformer. In the typical application, namely input voltage of 48 V, output voltage of 1 V, and switching frequency of 500 kHz, the peak efficiency is 94.84%.

关 键 词：降压变换器 飞电容 高转换比 软开关 效率提升 

分 类 号：TN86[电子电信—信息与通信工程] TN433