TOP249Y CONDUCTED EMI PROBLEM
Hi;
We have built SMPS with TOP249 IC. But we have failed conducted EMI test. There is a peak at 16.77 MHZ.
(generally between 16-17 MHZ ). I have attached schematic and test result with to different EMI filter.
Do you have any suggestion to solve this problem ?
Comments
Hi;
Im using smps design that designed by former engineer.
So i have got no idea about those components's function(R3,C6) . If you think R3 and C6 not necessary
for design , we can remove them. Also I have attached smps transformer datasheet. Thanks for
your valuable suggestions.
| Attachment | Size |
|---|---|
| SMPS transformer.pdf (226.49 KB) | 226.49 KB |
Hello,
you can try to see the EMI performance with removing R3 and C6 to see if there is any difference. In this way, we can find if these two components are the source of the noise.
You can also adjust the other components value to see where it will give you the most siginificant improve to find the source of the noise. then we can adjust base on that.
Best Regards
Hello serdarg,
Thank you for considering using Power Integrations Product.
Before we dig in, i have two question about the design.
How much is your transformer inductance?
Why you use R3 and C6, the RCD clamp is not enough?
Best Regards