一种多模式准谐振反激式变换控制器的设计

针对全负载条件下电源的转换效率问题，提出了一种反激式准谐振控制器的设计。该系统采用Quasi—Resonant／FFM／BURST多模式控制策略，在重栽时采用准谐振软开关；在中载时采用频率回扫（FFM）模式；在轻栽和空载的情况下采取BURST模式。控制器通过前馈控制消除了输入电压对输出电压的调制效应，提高了系统的动态响应；同时，采用反馈控制实现了对输出电压的精确控制。在1．5μmBCD（bipolar—CMOS—DMOS）工艺下完成了系统设计和仿真验证，仿真结果表明该控制器实现了预期的性能要求。

Design of multi-mode quasi-resonant fly-back SMPS

Aiming at the improvement of conversion efficiency over entire load range,a novel DC-DC fly-back multi-mode converter controller was proposed.The multi mode control strategies of Quasi-Resonant/FFM/BURST were used in the system.In heavy load condition,Quasi-Resonant mode was adopted;in moderate load condition,frequency fold back mode(FFM) was adopted;while in light load and non-load conditions,BURST mode was adopted.Feed-forward was used to reduce input to output modulation and improve the dynamic response....