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REF5040: EMC issues

Part Number: REF5040
Other Parts Discussed in Thread: REF3140

This customer has failed EMC testing and identified the REF5040 as being the culprit. Once the device is replaced with REF3140, the board passes the test. Can you please provide any insight to possible reasons? This voltage reference is used for an ADC. We are still working to get more details and possibly a schematic. The marking on the device is 55H Z203. Can you tell us the date of manufacture?

Thank you!

  • Hi Lenio,

    hhm, good design practise would be to have the voltage reference deeply "buried" in the circuit, enclosed in proper shielding, filtering and protection. Then it would be very improbable that the voltage reference makes a product fail the ce-testing...

    Anyway... The REF5040 has a larger package than the REF3140, SOIC8 compared to SOT-23. So, the REF5040 offers a larger surface area susceptible to attack, or by other words, a larger loop area susceptible to radiation. The REF5040 also routes more of the internal circuitry to the package pins. This also increases the suseptibility to EM interference.

  • Can you please send me an email so I can send you schematic and layout for review?
  • Hi Lenio,

    I agree with Kais comments regarding EMC issues. I have e-mailed you Lenio to take this offline in regards to customer information.

    -Marcoo Z