正激式变换器轻载条件下的同步整流分析(英文)

Synchronous Rectifier Analysis of Forward Converter under the Condition of Light Load

针对具有同步整流的正激变换电路在轻载条件下 ,因输出滤波电感电流经同步整流MOSFET管反向流动而形成环流的现象 ,提出了利用UC384 2检测轻载条件 ,并通过禁止续流MOSFET导通来阻止电感反向电流的技术方案 ,理论分析和实验研究证明该方法是可行的 。

While the converter works at light load, the output filter inductor current will go negative through MOSFET in synchronous rectifier and the circulating current will be formed. In order to solve this problem, the detection method of light load condition of converter used by UC3842 is proposed in this paper, meanwhile, the technique has also been studied which is used to make the inductor current cannot be flow negatively by switching off the MOSFET while converter works at light load. The theory analysis and experiment have proved that the proposed method is effect, the converter efficiency has also been improved a lot at light load.