TPS650842EVM-116: TPS650842 date code & marking code.

Hugo Liu

Part Number: TPS650842EVM-116

Hi Sir,

Our customer response the TPS650842 have D/C issue,
Old product used D/C1621(Marking code 791) no issue,
But same Layout & Schematic use D/C1748(MArking code 7BI) Will similar OCP or Shut down issue,
Does any difference of D/C1621(Marking code 791) & D/C1748(MArking code 7BI) version?

Hugo

over 7 years ago

0 Krishnamurthy Hegde over 7 years ago

TI__Expert 8730 points

Hi,

I have assigned your request to responsible Applications Engineer and we will get back to you as soon as possible.

Regards,

Murthy

0 Kevin LaRosa over 7 years ago

TI__Genius 17380 points

Hi Hugo,

There have been no changes to the TPS65084 2 between those dates.

Can you provide any more details, including oscilloscope shots, of the failures they are seeing?

0 Hugo Liu over 7 years ago in reply to Kevin LaRosa

Genius 5095 points

Hi Sir,

Thank you very much.
After checking with RD, I think this issue is from Layout.
if Buck 1 switch signal too close VFB trace, then we can see the Vout have noise similar switch signal. Iout over 3A Vout will turn off.

except cut trace to jump, How to improve this issue?filter or any suggest?

Hugo

0 Kevin LaRosa over 7 years ago in reply to Hugo Liu

TI__Genius 17380 points

Hi Hugo,

Customer could try adding filters on the FB net, though if FBVOUT1 and SW1 are closely parallel then no amount of filtering is likely to help. Generally we'd recommend something like 100 nF capacitor near the FBVOUT1 pin and some small series resistance (~1-10 ohm) between the cap and the noise source.

0 Hugo Liu over 7 years ago in reply to Kevin LaRosa

Genius 5095 points

Hi Sir,

Thank you very much.

Hugo

0 Hugo Liu over 7 years ago in reply to Kevin LaRosa

Genius 5095 points

Hi Sir,

We have check customer layout found out some issue of between SW & FB, The situation has improved.
but still have shut down afer test, Could you please help me double check the layout file?

Hugo

0 Hugo Liu over 7 years ago in reply to Kevin LaRosa

Genius 5095 points

Hi Sir,

Our customer release new version Layout for me today, we will provide our suggest first.

because have 1010 pcs product & 1700 PCB need to rework now,

Could you please help double confirm the layout?

Hugo

0 Kevin LaRosa over 7 years ago in reply to Hugo Liu

TI__Genius 17380 points

Hi Hugo,

Find attached a Schematic and Layout checklist which should help in your initial review. TPS65084x Schematic Checklist, Layout Checklist, and ILIM Calculator.xlsx

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TPS650842EVM-116: TPS650842 date code & marking code.