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UCC25600 LLC空载电压稳不住..请问有何建议
IC进入burst mode了,但电压还稳不住
输出波形传上来看看
波形没有存储起来,
波形就是:一个高一低地循环打嗝,电压往上飙..
加点死负载，再不就调整光藕上端的电阻参数，或者变压器匝比。
大多是前面没处理好，看看芯片的波形怎么样
Hi
能否将电路图上传上来看一看？
加假负载试试
都试过了,无效..
就是典型电路啊,,
检查一下反馈环路吧
轻载的环路有问题
轻载的环路有问题?
有什么对策?
大概问题出在哪里?
怀疑是电压环带宽轻载比较小，先测测电压环吧
I found that due to working in the burst mode, the energy of the aux_Vcc supplied by auxilliy wiring is not enough to keep Vcc stable.
it seem that it is regardless of Loop gain.
Burst mode本身就是重启过程，Vcc也会反复充电
进入burst mode的深度较深,,Vcc能量ripple voltage 太多,ic不断重启,
改变供电方式,
轻载时候由PFC 那边的VCC供电于PWM ic,可以解决空载下(进入burst mode)输出电压不稳问题..
