反激式开关电源控制芯片中的高精度原边反馈技术

摘要

This paper presents a high accuracy primary side feedback technology,which can be used in a flyback controller IC,It can auto track the knee voltage of the auxiliary side voltage (Vsense) and converts this voltage to digital single (VFB) that can be sent to a digital compensator.The digital compensator of the controller IC adjusts the output voltage according to the VFB.In order to verify the presented technology it has been designed with csmc0.18μm process .%本文提出了一种用于反激式开关电源控制芯片的高精度原边反馈技术,可以自动追踪原边辅助绕组电压的膝电压位置,得到高精度的反馈电压并将其进行模数转换输出反馈量VFB,控制芯片中的数字补偿模块根据VFB的值调节开关管的导通时间,最终实现输出电压的精确调制.本文提出的反馈技术采用csmc0.18μm工艺实现,验证结果显示本设计可以很好的检测到膝电压,实现了精确的原边反馈.