TPS2596: TPS259631 reverse powered

Massimo Romano said:

i wanna power my circuit using OUT to IN path

HI Massimo,

Can you please explain what you mean by this. Our devices are designed to have current flow from IN to OUT. 

Limiting the current at 0.3A is possible and can be done by selecting ILIM pin resistor. Schottky diode helps in preventing negative voltage during transient event. 

Do you require reverse current protection? 

Best Regards,
Arush

Yes, sorry.

I want to have the opportunity to power my device from one of it's output.

Until now i limited the output current to 0.3A (current flow from IN to OUT) and there was no need for this feature.
Now i want to know if there is any problem to make it flow backward (from OUT to IN). In any case I can place a diode in parallel from OUT to IN, in order to bypass the internal Mosfet body diode and almost totally avoid the current to run from OUT to IN(lower foward voltage drop).


I was asking, this diode i placed to power up my device from one of its output is necessary? Does a current da flows from OUT to IN may damage the TPS2596 or i can freely use it "unproperly"?

If i put the diode, the probably negligible current that occasionally flows from OUT to IN may result in a problem for the TPS? (i don't think so).

Actually i tested a small reverse current (50mA) without parallel diode, and seems no problems.

Thanks-

M.

Hi,

I think I finally understood your question. Can you please confirm my understanding. 

You want to allow reverse current of 0.3A, and you can place external diode but will prefer if the body diode of device itself can handle this. You are asking about the body diode specs like current handling capabilities to ensure that this won't damage the device. Am I understanding this correctly? 

I will get back to you with the body diode current handling capabilities after your confirmation.

Best Regards,
Arush

Yes almost correct, i'm limiting current flow from IN to Out so through the device. I don't really need the current limit from Out to IN, that is why actually i have the same design of your picture, but with a schottky diode with low foward voltage, bypassing the TPS.

So yes, you can consider your picture correct speaking about the problems that a current backflow can cause. :)

Thank you

Hi,

So, I will ask the designer of this part about the body diode current capabilities and will get back to you early next week.

Thank you,
Arush

Ok, for now i will place a schottky diode like your picture in order to power my device from its output, if not needed i will remove it later :)

Okay, understood. Meanwhile, I will follow up on this internally.

Best Regards,
Arush