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UCC14341-Q1: EMI

Brian Wang0928
Genius 14030 points
Part Number: UCC14341-Q1

Tool/software:

Hello, 

There're some filter workaround for the EMI/RF on the 6xMagnetoMV board made from BU Manuel Alva.

I'd like to confirm if these passive EMI components are necessary or not? How the EMI performance when they're removed? Or any suggestions to simply the circuit and layout area?

For the Below EMI performance, what's the background performance when POWER OFF?

Also, here're with 6x MV device, how's the performance with 10x MV? Is there any difference?

Bel Thanks.  

Regards

Brian

  • 0
    TI__Mastermind 32805 points

    Brian,

    With reference to the report you are showing, yes - the EMI passive components are necessary to pass CISPR 25, class 5 CE and RE. Many automotive OEMs introduce variations of the CISPR 25 EMI standard that their equipment must pass. The report you are showing demonstrates a feasible path for passing CISPR 25, class 5 CE/RE using typical passive components and shielding/grounding/pcb techniques found to be acceptable by many automotive OEMs. Also you can see in the title slide that the EMI scan is "6XMagnetoMV" where the "6x" indicates 6 ICs operating. For 10x the EMI input line filter would need to be scaled accordingly to handle the additional input current according t the max power demanded by the gate drivers/discretes.

    Steve

  • 0 in reply to Steven Mappus1
    TI__Genius 14030 points

    Thanks. One more question here.
    Based on my understanding, if the background EMI noise is zero and 6 ICs are operating, would there be approximately 40dB of noise at 150 kHz?

    Regards

    Brian

  • 0 in reply to Brian Wang0928
    TI__Mastermind 32805 points

    The ambient noise floor of the CE scan near ~150kHz is not ideal, since it is measuring ~40dB. I am using this lab setup for relative CE measurements during pre-compliance, EMI debug. No, the ambient noise floor measuring near ~40dB does not mean that if the ambient noise floor were 0dB in the 150kHz range, there would be a harmonic with 40dB amplitude. It does mean that if there were EM emissions near ~150kHz but below ~40dB, my setup would not be able to measure those. For example, there could be a peak at ~150kHz that is less than ~40dB and we can't see it in the scans I attached but if the noise floor were reduced to 0dB, then it would appear in the scan. Think of it like a mountain peak below the surface of the ocean. If you could reduce the level of the ocean, the peak would then be revealed.

    Steve