TS12A12511: TS12A12511DRJR power supply -5V overcurrent on PCB brd

wei wang91

Part Number: TS12A12511

Hi experts.

We met a strange issue with the application of TS12A12511DRJR. Submit a help thread before, but no finding, so we continue to debug it .

We use +5V , -5V power TS12A12511DRJR to pass -4 - -1 volt voltage. When we power TS12A12511DRJR. , -5V power overcurrent.

We follow datasheet simple circuits, with thermal via connect to GND.

So , we did some debug :

1: isolate +5V ,-5V power from other circuits, only to power TS12A12511DRJR

2: only power on +5V , it is ok, not overcurrent.

3:only power on -5V, it overcurrent . We removed -5V path capacitor, same result , overcurent.

2 questions from us:
1: thermal via connect to GND is ok?

2:only power on -5V is not a normal procedure ? so ,overcurrent is expected ?

3: if only power on -5V is ok, what 's the answer for -5V overcurrent?

thanks a lot.

over 7 years ago

0 wei wang91 over 7 years ago

Prodigy 90 points

4: if only power on -5V ,this action will permanently damage TS12A12511DRJR?

0 wei wang91 over 7 years ago in reply to wei wang91

Prodigy 90 points

Hi experts

we found "The Exposed Thermal Pad must be electrically connected to V– or left floating."
So, it means we connnect thermal via to GND is the root cause?

0 Adam Torma over 7 years ago in reply to wei wang91

TI__Mastermind 45400 points

Wei,

The thermal pad is internally connected to V- and must be connected to V- or left floating. If you have -5 V on the V- pin and the thermal pad connected to ground you will create a 5V short to ground through the IC. You should see the overcurrent issue go away if you connect the thermal pad to your lowest voltage node -5V.

Please let us know if this doesn't solve the issue.

Thank you,

Adam

0 wei wang91 over 7 years ago in reply to Adam Torma

Prodigy 90 points

thanks Adam, i think it shoulb be the roort cause. at the beginning of project, i asked chinese TI engineer he told me it can be conncected to GND.
we will have next PCB buit, and will try it, and let you know the result. thanks a lot.

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TS12A12511: TS12A12511DRJR power supply -5V overcurrent on PCB brd