LM5012-Q1: EMC issues

Norbert Nestler

Intellectual 340 points

Part Number: LM5012-Q1

Tool/software:

Hi to TI support team,

i did this design, which works well now but with some emc problems.

The emc test engineer recommends, to populate a 2.2nF capacitor parallel to R21 (RT/SYNC) resistor.

He said, this improves emc conducted emission. Are there any concerns about populating this capacitor?

Kind regards

Norbert

8 months ago

0 Nityanand Hegde 8 months ago

TI__Expert 5490 points

Hi Nobert,

It is not recommended to connect the capacitor across the RT/SYNC resistor. BTW which EMI is faling? Is it Radiated emission or conducted emission?

Thanks,

Nitya

0 Norbert Nestler 8 months ago in reply to Nityanand Hegde

Intellectual 340 points

Hi Nitya,

it's radiated emisson. Test engineer say's with the capacitor populated, emission is less at high voltages (60V) and the circuit is more stable.

Regards

Norbert

0 Nityanand Hegde 8 months ago in reply to Norbert Nestler

TI__Expert 5490 points

Hi Norbert,

Ask test engineer to place the capacitor very near to the input and output pin of the device and test it. BTW do you have plot and at what frequency the EMI is failing?.

Also please share schematic and layout of the device.

Thanks,

Nitya

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LM5012-Q1: EMC issues