TPS63002 damages easily in production

G M

Intellectual 265 points

Other Parts Discussed in Thread: TPS63002

Hello,

We're using TPS63002 to generate 5v / 0.5A (peak) from Li-ION battery (see below schematics)

We see that the device is damaged in high percentage ~40%!!! in production.

In a functional circuit, we can see 5v on VOUT_5V and measure large resistance [Kohm] between L22 and GND.

In failing circuit the VOUT_5V is at 2.3V and we see short ~58 [ohm] between L22 and GND, in parallel to high current consumption.

manually removing each device and soldering a new one solves the issue permanently.

We've manufactured ~70 units till now.

Any idea what might be wrong ????

Any replacement IC that might not be that sensitive???

Thanks in advance for your help!

Gal

over 8 years ago

0 Florian Feckl over 8 years ago

TI__Expert 7110 points

From your description it seems as IC's get destroyed. Your high failure rate points to a systematic issue.
Can you please share your layout?

0 G M over 8 years ago in reply to Florian Feckl

Intellectual 265 points

Thanks for your reply Florian. I will update with layout, is there specific format or info you're looking for?
also, do note that manually replacing the IC solves the issue permanently, no I'm not sure how it may be schematic issue.
Thanks

0 Florian Feckl over 8 years ago in reply to G M

TI__Expert 7110 points

Just uploading a PDF of the dc/dc part should be helpful.

Can you exclude soldering issues during manufacturing?

0 G M over 8 years ago in reply to Florian Feckl

Intellectual 265 points

please see layout pic attached.

No, I can't exclude soldering issue, but it is less likely since manufacturing is made automatically (not manual) and was made by two placement companies that yielded similar fail rate.

Any idea?

0 Sabrina over 8 years ago in reply to G M

TI__Expert 8420 points

I would recommend to follow the layout guidance of the datasheet (chap 10) for placing the input AND the ouput caps.
Especially, on the layout I see the C64 input cap is placed far away from the Vin pin, and this could be really critical. Also I would recommend to rotate the C120 input cap of 180° so that the ground pad is near the IC.

Moreover, why are the pins of the power pad of the IC isolated from the ground plane on the top and the bottom?

Power management

Power management forum

TPS63002 damages easily in production