同步整流技术在正激变换器中的应用研究

Research of Synchronous Rectification in Forward Converter

栅极电荷保持的方法可以解决传统自驱动同步整流的正激变化器在变压器电压死区时间的驱动问题,但同时会带来变换器出现直通的问题,本文提出了一种解决该问题的方法,另外本文还对外驱同步整流的驱动调节进行了探讨,并且阐述了同步整流中电流检测和轻载时候的问题。

The problem that conventional self-dliven synchronous rectification forward topology cannot provide drive voltage for freewheeling synchronous rectifier （SR） when transformer magnetic reset process is over and zero voltage appears across the transformer windings can be solved by using the gate charge retention drive method. But it also brings about the possibility that the transfomaer be shorted. In this paper, a method is proposed to selttle the problem. Besides, this paper talks over the drive method with IC, attentions in current sense and the issue in light load of synchronous rectification.