TPS631000: Query on the Reverse Current Operation

Hi  Davis,

you got a misunderstanding about the reverse current.

when the output voltage is higher than the set one. E.X, you set a 3.3V output, but the actual output voltage is higher than the set one, such as 4V. then the voltage of FB pin will higher than the ref internal. device will try to decrease the output voltage by a reverse current. no matter if vin is lower than Vout or not.

Regards

Tao

Hi Tao.

Have a nice day,

I understood that there is no dependency of vin, vout voltage on this reverse current. But depend on the feedback voltage.

But in the case of a reverse current will there be any spike or dip on the input voltage. In my case this buck-boost can source by qualcomm PMIC(option 1) or from a Li battery(As a option 2). Need to know whether there will be any issue to this sources due to the mentioned reverse current.

Hi  Davis,

Sorry for the misunderstanding. 

for device, this reverse current should  be ok. but if the source current from PMIC is higher the reverse current which device can deal with, the output voltage will rise up continously and if the final voltage is higher than the spec. device may damaged.

for the reverse current itself, that should be ok for device, there is a limit internal for reverse current as below.

Regards

Tao

HI Tao,

Thanks for the clarification. Let me know if you have any buck boost with 1A current out without this reverse current feature

Hi Davis,

How about set the device work with PFM mode, then there will be no reverse current.

my concern is that without reverse current, output voltage may too high to damage the device if there is another source connected to output.

Regards

Tao

Hi Tao,

There will be no source connected to the regulator output. Let me know your thoughts

Hi Tao,

For part  TPS630242. I didn't see the discussed reverse current issue to this part. Can you also check?

Hi  Davis,

sorry. I did not find any info too.

Regards

Tao

Hi Tao,

Its good. Since it don't have the reverse current problem i can use TPS630242.