TPS61070: TPS61070DDCR SW pin short to GND

JeffYC Yang

Part Number: TPS61070

Hi Jasper,

My customer have meet TPS61070 damaged issue, they found SW pin short to GND, fail rate about 3%, total 50/1400.

Schematic as below, customer said they have meet this issue before, but they change the inductor from 4.7uH to 3.3uH, seems solve this issue, but now used 3.3uH but still found damaged in this project.

Do you have any idea about this? Human finger is possible let the IC damaged(I saw the FB pin sensitive issue on E2E, if finger touch caused Vout raise up)? or have you meet this SW pin damage issue before?

Or any information need I provide please let me know.

thanks!

Jeff

over 7 years ago

0 JeffYC Yang over 7 years ago

Expert 1290 points

Hi Sir,

Any idea for this issue?

Thanks!
Jeff

0 Jasper Li over 7 years ago

TI__Mastermind 46905 points

Could you share the layout of boost converter?

0 JeffYC Yang over 7 years ago in reply to Jasper Li

Expert 1290 points

Hi Jasper,

please refer to below.

0 Jasper Li over 7 years ago in reply to JeffYC Yang

TI__Mastermind 46905 points

The routing of the IC's GND pin and the output capacitor ground node is long and not strong enough, which could cause high spike at SW pin and damage the IC. i would suggest to place a output capacitor on the right side near the IC, and connect the capacitor with the IC without using vias.
or add snubber circuit to reduce the SW voltage spike.

Power management

Power management forum

TPS61070: TPS61070DDCR SW pin short to GND