TPS563201: Output shorted to ground, internally

Art Mecina

Part Number: TPS563201

Hello Guys,

Good day.

Our customer have encountered several failures on their newly built boards using TPS563201DDCR where the output gets internally shorted to ground. They want their layout be reviewed. They have only provided us with the attached file. Would this be enough?

Thanks!

ArtTI_Case_CS0277357-2.docx

over 5 years ago

0 Vincent Zhang(BSR) over 5 years ago

TI__Expert 4795 points

Hi，

What‘s the failure Vin/Vout/Iout condition？Do you mean SW short to GND or VIN short to GND?

0 Art Mecina over 5 years ago in reply to Vincent Zhang(BSR)

TI__Genius 16655 points

Hello Vincent,

Thank you for the prompt response!

I will direct the customer to this thread so that he can explain the chips fail scenario.

Art

0 Bill Drouin over 5 years ago in reply to Vincent Zhang(BSR)

Prodigy 50 points

Hi Vincent, yes the output is internally shorted ground we have seen this now on 3 units.

0 Gerold Dhanabalan - Online Design Tools over 5 years ago in reply to Bill Drouin

TI__Genius 14455 points

Hi Bill

Can you please confirm if the output short to ground was measured between the SW pin and GND or between the Vout and ground?

Regards,

Gerold

0 Gerold Dhanabalan - Online Design Tools over 5 years ago in reply to Gerold Dhanabalan - Online Design Tools

TI__Genius 14455 points

Hi Bill,

Also the image you attached did not come through. Can you please reattach?

regards,

Gerold

0 Yuchang Zhang over 5 years ago in reply to Bill Drouin

TI__Mastermind 18510 points

Hi,

The layout is not good, the input caps should be placed across the VIN pin and PGND pin, but now is very far away, which will cause high VIN/SW spike. the IC may be damaged if the spike is high enough.

Suggest you optimize the layout follow EVM/datasheet guide. also suggest you upload the schematic for review.

Yuchang

0 Bill Drouin over 5 years ago in reply to Gerold Dhanabalan - Online Design Tools

Prodigy 50 points

For all 3 units, with the device removed from board, pin 1 (GND) is shorted to pin 2 (SW)

0 Bill Drouin over 5 years ago in reply to Gerold Dhanabalan - Online Design Tools

Prodigy 50 points

0 Yuchang Zhang over 5 years ago in reply to Bill Drouin

TI__Mastermind 18510 points

Hi,

If you have the failure conditions that should be more helpful for analysis, Vin/Vout/Loading...

So far the damage is possibly related to the bad input cap layout placement.

The layout must be updated.

12Vin line with copper plane.
input cap(C51?) should be placed across VIN/GND pins as close as possible with copper plane.

Also could you please upload schematic fro review?

0 Bill Drouin over 5 years ago in reply to Yuchang Zhang

Prodigy 50 points

0 Yuchang Zhang over 5 years ago in reply to Bill Drouin

TI__Mastermind 18510 points

Hi, Your upload is not successful, please retry with attachment.

0 Bill Drouin over 5 years ago in reply to Yuchang Zhang

Prodigy 50 points

TI_Case_CS0277357_4.docx

0 Yuchang Zhang over 5 years ago in reply to Bill Drouin

TI__Mastermind 18510 points

Hi, schematic looks ok, just suggest to reserve cff like C4 in fig19 of datasheet. so possibly the reason is the bad layout.

Suggest you try to duplicate the issue and optimize the layout follow TI EVM and re-check the issue with same duplication test way.

Yuchang

Power management

Power management forum

TPS563201: Output shorted to ground, internally