TPS51397A: IC failure in startup condition

Embedded Boatload

Prodigy 40 points

Part Number: TPS51397A

Hi,

I used webench® power designer tool to design 12V to 3.3V Buck regulator for our product.

I choose Buck regulator Circuit with TPS51397A IC based on all simulation results.

PCB Layout design followed according to Datasheet Layout guidelines.

But, IC failed miserably during Startup Condition and unable to generate 3.3V.

I have shared Schematic and Layout details for your reference.

Kindly advice.

9 months ago

0 Aurora Tie 9 months ago

TI__Genius 12720 points

Hi,

I checked on webench, and I see the recommended inductance value is 1.8uH. But you use a 8uH inductor? Can you try to change it? Thanks.

Aurora

0 Embedded Boatload 9 months ago in reply to Aurora Tie

Prodigy 40 points

Hi,

Thanks for highlighting the change. But, it was only schematic error from my end. In actual, I have used 1.8uH as recommended from TI.

TPS51397A_BUCK_CONVERTER_WEBENCH_REPORT_V0.1.pdf

Based on report, I continued schematic and Bill of Materials for PCB layout design.

Kindly advice how to troubleshoot the issue with your expertise.

0 Aurora Tie 9 months ago in reply to Embedded Boatload

TI__Genius 12720 points

Hi,

Can you test the waveforms of each pin first? Check whether the EN, VCC, VIN and Mode voltages are normal. Especially the VCC voltage. Then use a differential probe to test the voltage waveform on the BOOT capacitor. In addition, please use a multimeter to measure whether the ESD diodes with different pins to ground are present, and make sure there is no problem with the chip welding. You can update me with the results of your test. Thanks.

Aurora

0 Embedded Boatload 9 months ago in reply to Aurora Tie

Prodigy 40 points

Sure. Thanks for your Prompt response. I will share the Measurement Results for next proceedings

0 Aurora Tie 9 months ago in reply to Embedded Boatload

TI__Genius 12720 points

OK, if you have test results, you can share them to me. Thanks.

Aurora

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TPS51397A: IC failure in startup condition