UCC28711: EMI Filter

Ray Vincent Aranzaso

Part Number: UCC28711
Other Parts Discussed in Thread: LM5023, PMP11135

Hi,

Good Day. I have a customer who is working with UCC27811. Please see below his query for your reference. Thank you very much.

I have designed an SMPS using UCC28711 with WEBENCH platform. I just want to know that is there need of an EMI filter as WEBENCH design have not included it for UCC28711 but it shows EMI filter at input for other ICs like LM5023. Thus please guide, if EMI filter is required in the input for enclosed design.

Best Regards,

Ray Vincent

over 2 years ago

0 Wesley Hsu over 2 years ago

TI__Expert 3431 points

Hi, Ray:

Thanks for asking.

Yes, EMI filter is needed. You may refer PMP21927 and PM1135.

Regards,

Wesley

0 Ray Vincent Aranzaso over 2 years ago in reply to Wesley Hsu

TI__Genius 14525 points

Hi Wesley,

Good Day. Please see below the response of our customer to your query. Thank you very much.

"Just want to ask that in design PMP11135 which is a 12W output design, the EMI choke is indicated as DNP. Thus is it not necessary in lower power design or does it depend on switching frequency?"

Best Regards,

Ray Vincent

0 Wesley Hsu over 2 years ago in reply to Ray Vincent Aranzaso

TI__Expert 3431 points

Hi, Ray:

Generally for low power <15W, pi filter (C1/L1/C2) is enough for low power for most of time. Customer can choose either one of them for low power. For higher power, the EMI filter like PM21927 is necessary. I would suggest keep the space for EMI filter in prototype, and remove it if EMI would be solved by pi filter, which is like PMP11135 did.

If the power rating is higher, please refer the PM21927's design.

Regards,

Wesley

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UCC28711: EMI Filter