TPS610982: Protection circuit question to EIPD

CHO SR

Genius 3375 points

Part Number: TPS610982

Hi,

The customer is using TPS610982.

Continuous field defects are occurring. The report result is EIPD.

The customer wants to add a protection circuit to improve EIPD.

Please give me the protection circuit guide for EIPD improvement in schematic.

over 2 years ago

0 Wenhao Wu over 2 years ago

TI__Genius 9046 points

Hi Cho,

Could you please share me with their layout? Thank you very much for your reaching out!

-Wenhao

0 CHO SR over 2 years ago in reply to Wenhao Wu

Genius 3375 points

Hi Wenhao,

I have attached the file.

0 Wenhao Wu over 2 years ago in reply to CHO SR

TI__Genius 9046 points

Hi Cho,

Could you please send me screen shot instead? I am not able to open your attached file.

-Wenhao

0 CHO SR over 2 years ago in reply to Wenhao Wu

Genius 3375 points

Hi Wenhao,

I have attached the pdf file.

0 Wenhao Wu over 2 years ago in reply to CHO SR

TI__Genius 9046 points

Hi Cho,

I think the layout looks fine. The distance between IC and output capacitor is ok, but capacitor's value has limited its effect in de-coupling Vout look. Could you please change value of C32 to 2.2uF/0603?

-Wenhao

0 CHO SR over 2 years ago in reply to Wenhao Wu

Genius 3375 points

Hi Wenhao,

Thank you.

Is there any additional protection circuit?

+1 Wenhao Wu over 2 years ago in reply to CHO SR

TI__Genius 9046 points

Hi Cho,

Yes, consider this is a SW-GND short. The most possible reason I have seen is the stress to LSFET. There are multiple ways to confirm the minimize the stress:

1.Measure the SW-GND voltage using minimum loop method. Use maximum scope bandwidth, maximum probe bandwidth to measure this voltage.

Minimum loop method:

2.If SW voltage is confirmed too large(above 4.2V). Place a R-C snubber between SW and GND. This would decrease the stress to LSFET. You need to measure and check the spec of snubber on your real board. Usually I start from 2.2Ohm/0603+1nF/0402.

-Wenhao

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TPS610982: Protection circuit question to EIPD