TPS51396A: Component sort circuit during power on/enable

Dim_Spa

Part Number: TPS51396A

Hi,

I have a problem with the IC TPS51396A when I try to power on. After enable a sort circuit is created between VCC #17 with GND .

On my design I have 5 same IC TPS51396A. The problem is the sort circuit is happening only on two specific of them every time.

There are two ways to enable them.

Either with 5V voltage rail, it is generated after Vin pgood.
Or with external controller providing 3.3V

Both of them are failing.

Could you please provide insight about what could be the root cause?

Schematic & layout attached.

Layout

Thank in advance,

over 1 year ago

0 Andrew Xiong over 1 year ago

TI__Expert 5470 points

Hi Dimitris,

Sorry that I didn't fully get your meaning.

For the short circuit between VCC and GND, do you mean TPS51396A is damaged? Or do you mean the measured voltage is 0V between VCC and GND?

I know that you have two enable logic to enable the circuit, have you measured the voltage of EN pin (node 2 of R292 or node 1 of R288) and checked if the EN voltage is correct?

Thanks,

Andrew

0 Dim_Spa over 1 year ago in reply to Andrew Xiong

Prodigy 40 points

Hello Andrew,

Yes, the TPS51396A is damaged.

I don't have both resistors placed. The options are to feed the enable signal with R292 placed and the voltage is 3,3V or either placed R288 and the voltage is 5V.

Both options are damaging the IC and need to desolder it in order to have my board up again.

Thank you,

0 Calan Elaya over 1 year ago in reply to Dim_Spa

TI__Genius 11285 points

Hello,

A response will be posted next week.

Thank you,

Calan

0 Dim_Spa over 1 year ago in reply to Calan Elaya

Prodigy 40 points

Any update ?

0 Aurora Tie over 1 year ago in reply to Dim_Spa

TI__Genius 16830 points

Hi,

Sorry for the late reply. I will reply to this thread. Let me check your schematic and layout and give you some feedback later. Thanks.

Aurora

0 Aurora Tie over 1 year ago in reply to Dim_Spa

TI__Genius 16830 points

Hi Dimitris,

I took a look at the previous communication, and I want to confirm with you whether the current chip will be damaged as soon as it is powered on? Or will it be damaged under the some conditions? Are there some waveforms at the moment of damage?

In addition, you said that you are currently using 5 TPS51396A. Do all of them have the same problem? Looking forward to your reply. Thanks.

Aurora

0 Dim_Spa over 1 year ago in reply to Aurora Tie

Prodigy 40 points

Hi Aurora,

Answer #1:

Yes the chip is damaged as soon as it is powered on.

Answer #2:

No I didn't notice any waveforms.

Answer #3:

Not all of them the 2 of them.

0 Aurora Tie over 1 year ago in reply to Dim_Spa

TI__Genius 16830 points

Hi Dimitris,

Are the 5pcs TPS51396A you are using in the same application or different applications? Are 2 of the same 5 boards damaged after being powered on? Are you sure there is no problem with the soldering? Looking forward to your reply. Thanks.

Aurora

0 Dim_Spa over 1 year ago in reply to Aurora Tie

Prodigy 40 points

I have designed one board with 5pcs of TPS51396A, on all my boards 2 out of 5 are damaged after being powered on, and it's always the same chips.

I have check solder paste and the via in pads are capped with copper.

0 Aurora Tie over 1 year ago in reply to Dim_Spa

TI__Genius 16830 points

Hi Dimitris,

Are these five TPS51396A schematics the same? If not, can you send me the schematic/layout with and without the problem? Also what are the conditions for each of their applications? Because based on your description it should be a problem with your board or application, not the chip itself.

Looking forward to your reply. Thanks.

Aurora.

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TPS51396A: Component sort circuit during power on/enable