MP2490 design - EMC issues

DC-DC Power Converters
1

Dear MPS Team,

We are now pretty happy with the performance of the MP2490 device and our implementation of the design which we have made very tight.

We are struggling a bit with EMC. We find that the supply readily interferes with the DAB radio in our lab and, when compared to a Murata PSU module, the radiated noise as measured on a near field probe is more than 3dB higher.

We have tried snubbing the output at the switch node, but this is not having much effect. Do you have any advice on how to get our EMC issues under control?

Many thanks,

Phil

2

Hello Phil,

Have you taken a look at your layout? Some common techniques are adding in more ground planes, making those grounds more compact, and minimizing loops. A good resource for you can be this video: Automotive EMI Demystified - Part 2: Pursuing An Ideal Power Supply Layout

Thank you,
Vinh Tran
Field Applications Engineer