• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 354 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

LM3150: EMC certification problem

Francesco Da Re
Intellectual 280 points
Part Number: LM3150

Hello,

we are experiencing some problem with switching spikes during CE certification.

Main source seems to be the two Mosfets driven by the LM3150.

We already have a 4 layer pcb with internal power planes and the layous seem to be correct . We followet the suggested applications note .

Adding a large (470uF) low ESR input capacitor halps but not solve.

In your AN you do not place any Snubber network. It should help, but I cant find any suggestion about it on the AN.

Do you have any suggestion?

Best regards

Francesco

scan0001.pdf

  • 0
    TI__Mastermind 34875 points

    Hi Francesco,

    Do you know at which freq the EMI result over CE limitation?

    Normally there should be L/C filter on input front end to filter out conduction noise, I don't see it on your design. pls download below file on TI website to improve your EMC  performance:

    Doc# SNVA489C :   AN-2162 Simple Success With Conducted EMI From DCDC Converters

  • 0 in reply to Andy Chen
    Intellectual 280 points

    Hello Andy,

    thank you for answering.

    I am going to read  AN 2162. Anyway My problems are only with radiated noise while conducted are ok.

    Best regards

    Francesco

  • 0 in reply to Francesco Da Re
    TI__Mastermind 34875 points

    Hi Francesco,

    Radiated noise is more challenging to handle with,  pls refer to below Application guides from TI website:

    AN-2155 Layout Tips for EMI Reduction in DC / DC Converters

    Low Radiated EMI Layout Made SIMPLE with LM4360x and LM4600x

    Reduce buck-converter EMI and voltage stress by minimizing inductive parasitics