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LM25149-Q1: How to disable the AEF?

Part Number: LM25149-Q1

Tool/software:

Hi,

I want to disable the AEF, just to compare the EMI measurement results. I am trying to do it by connecting a jumper pin between CNFG and GND AFTER startup. But it does not seem to work. What am I missing?

EDIT: I have a 24.9k ohm resistor between CNFG and AGND.

  • Hi Darious,

    Can you connect a Voltage source to CNFG that is below 0.8V?

    Thanks,

    Andrew

  • Hello,

    I do not have a 0.8V source in my possession. My design is identical to LM25149-Q1EVM-2100, but with components for 440 kHz switching frequency.

    The datasheet says tie CNFG to GND to disable AEF. But I am still getting the same EMI results. 

  • Hi Darius,

    It should only affect the conducted EMI. Can you try shorting out the the input pi EMI filter and try again? It might also be more noticeable if you try different frequencies or a lower quality inductor.

    Thanks,

    Andrew