TPS5450: EMI Peaks above the FCC part 15B limits

Dushan Kumara

Part Number: TPS5450

Tool/software:

Hi Experts

I am using the TPS5450DDAR step-down converter to obtain 3.3V from 12V. It powers a set of LEDs and the microcontroller on the PCB. Please see the schematic below. The issue is that radiated emission peaks are above the limit. Any suggestions for PCB modifications to improve this would be highly appreciated.

EMI Using near field probe

FCC 15B RE test output

Looking forward to seeing your response

Best regards

Dushan

8 months ago

+1 Andrew Kutzler 8 months ago

TI__Mastermind 19110 points

Hi Dushan,

You could try replacing C70 with a 100nF capacitor. Also You could try different shielded inductors from other vendors (Coilcraft, TDK, Murata, etc) and see if that helps.

Thanks,

Andrew

0 Dushan Kumara 8 months ago in reply to Andrew Kutzler

Intellectual 270 points

Thanks for your prompt response. I will try and send you the results

Best regards

Dushan

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TPS5450: EMI Peaks above the FCC part 15B limits