同步整流器中MOSFET的双向导电特性和整流损耗-中国电机工程学会.PDF

22 3 Vol. 22 No . 3 Mar. 2002 2002 3 Proceedings of the CSEE 2002 Chin. Soc.for Elec. Eng . (2002) 0300880 MOSFET 胡宗波, 张 波 ( 华南理工大学电力学院, 广东 广州510 40) STUDY ON BIDIRECTIONAL CONDUCTIBILITY AND POWER LOSS OF POWER MOSFETSIN SYNCHRONOUS RECTIFIERS HU Zongbo, ZHANG Bo ( Electric Engineering College of South China University of Technology, Guangzhou 510 40, China) ABSTRACT: For the first time this paper studies power MOS FETs bi directional conductibility and works out the complete bi directional I d- Vds output characteristics of power MOSFETs based : ; ; on theoretical analysis and experiments,w hich provides the basis for ; power MOSFETs practical application in synchronous rectifier. : TM 1 : A Since the efficiency of synchronous rectification depends on the recti fying dissipation of power MOSFETs, based on the equivalent power 1 loss model of power MOSFET , the interrelation of rectifying losses of power MOSFETs with model parameters, gate drive voltage Vgson , and switching frequency is exammed, and synchronous rectification efficiency characteristics are presented for the first time in this pa , per. In addition, rectifying losses in power MOSFETs and Schottkies , , are compared in high current output cases and the concept of parallel , connection of power MOSFETs is proposed in such cases. The work done will give much help in the choice of switching frequency, gate MOSFET drive voltage Vgson and singletransistor operation or multi transistor parallel connection of power MOSFETs . ,