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UCC28180: UCC28180D-RE CE EMISSION LIMITS TO MEET CLASS B level

Smitha R
Intellectual 790 points
Part Number: UCC28180

We are currently using the UCC28180D IC as  PFC controller in our power supply design(250W output) and we found the emissions(CE and RE) are more from the PFC circuit. 

Our current design fails badly to meet the requirement and it only meets class A level for CE and RE. our customer has asked to meet class B level for CE and RE

We have referred TI applications notes and evaluation board and found that the evaluation board supports only class A requirement.

Do you have any better suggestions to meet the above requirement? Please let me know ASAP.

  • 0
    TI__Mastermind 25570 points

    Hello Smitha

    Can you post a plot of the Conducted Emissions (CE?) and Radiated Emissions (RE?) results please.

    Low frequency CE emissions (<10MHz approx) are likely to be differential mode (DM) and improved DM filtering will be needed. Higher frequency CE emissions are likely to be Common Mode (CM). Attention to heatsink grounding and other CM sources would be needed. Do you have a second stage after the PFC ? - the isolation transformer in the second stage is likely to be a major source of CM noise.

    RE problems are more likely to be due to unclamped inductive spiking somewhere in the power stages -

    Do you have a schematic you could share?. If it's confidential then you could email it directly to me at colingillmor@ti.com.

    Regards

    Colin