TPS2372-3: ESD Test Comparison with TPS2372-4

Allan Fan

Part Number: TPS2372
Other Parts Discussed in Thread: TPS2373, , TPS23754

Hi Expert,

Customer used TPS2372-3 with non-isolated topology and want to pass 15KV system ESD test. It used in two models and passed.

They also built in TPS2372-4 as 2nd source direct replacement however the same ESD test were failed.

Customer have verified two actions:

1. it's still ok to power up the system with failed unit in DC supply, but can't make it with standard PSE. It's always in detection mode.

2. measured the failed unit, DEN pin seems damaged with low impedance ~15ohm(good unit is 0.65Mohm).

DS shows the ESD level between TPS2372-3 and TPS2372-4 are the same but wondering what might be possible reasons to cause the different result?

Model A:

TPS2372-3 ESD pass 17KV

TPS2372-4 ESD pass 14KV, fail at 15KV

Model B:

TPS2372-3 ESD pass 15KV

TPS2372-4 ESD pass 4KV, fail at 8KV

Thanks,

Allan

over 3 years ago

0 Michael Pahl over 3 years ago

TI__Mastermind 21320 points

Hey Allan,

Sorry to clarify, in the first description you mention they use the TPS2372 and TPS2373. In the bottom descriptions of Model A and Model B, the difference is the -3 vs the -4, only using the TPS2372. Can you clarify, is this failure observed between the TPS2372 & TPS2373, or is it between the -3 and -4 versions of the TPS2372?

it will significantly impact the investigation, so I want to be sure I understand.

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Allan Fan over 3 years ago in reply to Michael Pahl

TI__Expert 7300 points

Hi Michael,

Sorry for the typo and the misleading. I have made update in the original post. It should be TPS2372-3 vs TPS2372-4.

Regards,

Allan

0 Michael Pahl over 3 years ago in reply to Allan Fan

TI__Mastermind 21320 points

Hey Allan,

Thanks for clarifying. As you mention, the only difference between the two designs is the internal pass FET, one being rated for higher power. Does the design have a TVS in parallel with the body diode and one on VDD_VSS?

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Wilbur Cheng over 3 years ago in reply to Michael Pahl

Prodigy 30 points

Hi Michael,

We design have a TVS on VDD_VSS and reserve one inparallel with the body (DNI) as picture.

In the test results, the ESD susceptibility is different between TPS2372-3 and TPS2372-4.

Please help to provide your comments and suggestions.

Many thanks.

Wilbur Cheng

0 Michael Pahl over 3 years ago in reply to Wilbur Cheng

TI__Mastermind 21320 points

Hey WIlbur,

Can you try testing with the TVS? That is our recommended ESD protection.

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Michael Pahl over 3 years ago in reply to Michael Pahl

TI__Mastermind 21320 points

Hello,

Is there any update on the testing here?

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Wilbur Cheng over 3 years ago in reply to Michael Pahl

Prodigy 30 points

Hi Michael,

Thanks for your comment.

We will test is on new version PCBA later.

Please mark this thread as resolved.

Thank you.

Wilbur Cheng

0 Allan Fan over 3 years ago in reply to Wilbur Cheng

TI__Expert 7300 points

Hi Willbur,

One comment, the TVS between VSS_RTN should be unidirection, not bidirection.

Regards,

Allan

0 Wilbur Cheng over 3 years ago in reply to Allan Fan

Prodigy 30 points

Hi Allan,

We do the ESD test with TPS2372-3 and TPS2372-4 in new version PCBA.

Test-1, TPS2372-3 with one 58V TVS, Pass cable ESD 15KV.

Test-2, TPS2372-4 with two 58V TVS, Fail cable ESD 8KV. (Standard PoE cannot power on, Passive PoE is able to power on.)

We don't know why the TPS2372-4 fail the ESD test if TPS2372-3 and TPS2372-4 are the same ESD specification.

Please help to provide your comments and suggestions.

Many thanks.

Wilbur Cheng

0 Penny Xu over 3 years ago in reply to Wilbur Cheng

TI__Genius 15685 points

Wilbur,

Based on datasheet, TPS23754 passed ESD testing based on EN61000-4-2. Thanks.

Power management

Power management forum

TPS2372-3: ESD Test Comparison with TPS2372-4