TPS54528: SW short to GND issue and Schematic review

Robin Yu

Intellectual 2190 points

Part Number: TPS54528

Hi team,

It is already found about 10pcs among 20kpcs failed during production for TPS54528.

All of the are found SW short to GND even when the load is very small, only tens of mA.

Could you please help check the sch and layout to help check if there is any risk for the design?

I could provide the design file by email.

Thanks.

Robin

over 4 years ago

0 Zhao Ma over 4 years ago

TI__Genius 15135 points

Hi, Robin

You can send emails to me, zhao-ma@ti.com

0 Jenson Lam over 4 years ago

TI__Prodigy 450 points

Hi Robin,

I have reviewed your schematics, please see the recommendation shown below

1) TPS54528 is intended for use with ceramic low ESR capacitors, not electrolytic capacitors such as EC8, EC9. Please refer to section 9.2.2.2 of the datasheet.

2) Need to monitor the voltage at VIN pin and make sure it's stable.

3) Layout placement of decoupling caps (C8, C10, C13, C14) need to be close to device. Please refer to section 11.1 of the datasheet.

Regards,

jenson

0 Robin Yu over 4 years ago in reply to Jenson Lam

TI__Intellectual 2190 points

Hi Jenson,

Thanks for your reply.

One more question.

If electrolytic capacitors are used, the output ripple will be large, any risk to damage the device? stability?

Thanks.

Robin

0 Jenson Lam over 4 years ago in reply to Robin Yu

TI__Prodigy 450 points

Hi Robin,

The impacts are

- higher power loss

- DC shift

- cap value changes over time

- potential poor transient response

Regards,

jenson

0 Robin Yu over 4 years ago in reply to Jenson Lam

TI__Intellectual 2190 points

Hi Jensen,

Ok, but I could not understand why this will damage the device. Could you please explain it? Thanks.

Robin

0 Jenson Lam over 4 years ago in reply to Robin Yu

TI__Prodigy 450 points

Hi Robin,

Reviewing the schematics, I do not see any risk from it that causes damage. Please check the input and output waveform and make sure they look stable.

Regards,

Jenson

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TPS54528: SW short to GND issue and Schematic review