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.

UCD3138-PSFB EVM空载与死负载问题



您好,

最近在测试UCD3138-PSFB EVM,发现两个问题:

1、开发板空载和轻微带载时,初级开关管移相角差别很大。空载时,移相角很大。轻载和满载时,移相角很小,差别不大。

为什么这样?

2、若去除开发板上的死负载,输出电压会上漂。

为什么一定要加入20mA死负载呢?