This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM51551 FLYBACK设计,怎样改善提高开机时的电源带载能力?

Other Parts Discussed in Thread: LM51551

你好,请教怎样可以提高LM51551 FLYBACK设计,开机时的电源带载能力?

设计的输入电压是9~36V; 输出12V/5A;电路SCH如下图; 我使用一个约50W的负载做测试:

1,当输入电压调到高于26V输入时,可以正常开机启动;启动后,我把输入电压调到18V,此电源依然工作正常;输出是12V,平稳 工作;

2,当输入电压是22V以下时开机,电源不能正常开机,输出电压只有3~6V, 一直在跳动;

我使用的采样电阻是4个10 mOHM的并联,理论上远不到芯片保护的阈值 ;

请帮忙分析,怎样提高开机时的带载能力,谢谢。