UCC28600: UCC28600 Radiated emission issue

Vilas Shinde1

Prodigy 20 points

Part Number: UCC28600

Good Morning Sir/Madam,

We are using TI Switcher IC UCC28600 in our smps device (96Watts, 72Watts).

In this product we are facing the radiated emission issue. In this majeure failure at lower frequency.

We need your help to resolve radiated issue for the same.

Information about device:

1. 96 Watts

Input voltage :- 160VAC to 265VAC

Output voltage :- 24VDC

Output Current :- 4A

Radiated Emission :- CISPR 11 Class A

2. 72 Watts

Input voltage :- 160VAC to 265VAC

Output voltage :- 12VDC

Output Current :- 6A

Radiated Emission :- CISPR 11 Class A

Observe results :

Frequency (MHz)	QuasiPeak (dBuV/m)	Limit (dBuV/m)	Margin (dB)
31.53	64.09	50	-14.09
35.30	66.12	50	-16.12
56.60	65.63	50	-15.63
62.15	57.19	50	-7.19
67.72	52.90	50	-2.90

We are looking for your reply.

Thanks and Regards,

Manoj G,

Power App Dept.

GIC PVT. LTD. Pune

over 5 years ago

0 Ulrich Goerke over 5 years ago

TI__Mastermind 40580 points

Hello Vilas,

The issue of Radiated Emissions (RE) is a complicated one. Many aspects of the design may contribute to RE.

Please refer to this previous E2E thread with a similar issue. It involves a different IC, but the concepts are the same.

https://e2e.ti.com/support/isolation/f/1013/t/641165?keyMatch=RADIATED%20EMISSIONS&tisearch=Search-EN-everything

Your design may require one or more of the techniques mentioned in that thread. You may also try to correlate the RE frequency to some ringing or switching edge in the voltage or current waveforms and try to suppress or mitigate it there at the source. Look for long lead lengths and wide loop areas to reduce. Otherwise, containment is the only other option.

Regards,

Ulrich

0 Vilas Shinde1 over 5 years ago in reply to Ulrich Goerke

Prodigy 20 points

suggested answer is not exactly relevant to resolve radiated emission problem in power supply design.

Please assign expert to review the design. We are using ucc28600 in two different products which are already running in our production. Order quantity is also good and growing further.

Due to this failure we are not able to put CE mark on product. We are also trying to resolve this problem by designing alternate solution using some other make switcher IC which have in-built MOSFET.

Thanks & Regards

Vilas Shinde

0 Ulrich Goerke over 5 years ago in reply to Vilas Shinde1

TI__Mastermind 40580 points

Hello Vilas,

The link that I referenced is very relevant to radiated emission problems in power supply design, in my opinion, despite the fact that it involved a different kind of IC. The issues, techniques, test equipment, and possible remedies apply much the same to your specific supplies as they do to general switching circuits.

Due to the complexities of EMI design and difficulties of remote debug, your local TI Field Applications Engineer can provide assistance and will request the design files to provide to TI for review.

In addition, I suggest to review the following points to understand best practices for system design and EMI filter design and debug:

Layout guidelines in UCC28600 datasheet, Sections 10.1 and 10.2
Training video on introduction on EMI design https://training.ti.com/introduction-emi-power-supply-designs-sources-measurements-and-mitigation-methods?context=1134585-1139234-1136865
Detailed training series on EMI https://training.ti.com/emi-fundamentals
PSDS paper on transformer design to minimize EMI https://www.ti.com/seclit/ml/slup338/slup338.pdf?ts=1588601533948

Regards,

Ulrich

As I understand it, will request the design files to provide to TI for review.

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UCC28600: UCC28600 Radiated emission issue