TPS61252: Leakage current from VIN to VOUT & VF

user803572

Part Number: TPS61252

Hi Team,

If VIN and EN drop below ULVO (at shutdown), does a max 3.5uA leak occur from SW to VOUT through the body diode of the P-ch FET?
What is the maximum VF at that time?

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over 3 years ago

0 Wenhao Wu over 3 years ago

TI__Genius 9046 points

Hi Sir,

Shutdown current is measured at VIN=3.6V and EN=0, measure the input current from VIN. So when VIN is below UVLO, this is out of spec.

-Wenhao

0 user803572 over 3 years ago in reply to Wenhao Wu

Prodigy 40 points

Thank you for answer.
I understand that it is out of spec, but I would like to know the mechanism.

0 Wenhao Wu over 3 years ago in reply to user803572

TI__Genius 9046 points

Hi Sir,

Could I know the background? Why customer cares so much about this? What is the board you are using for the evaluation? I can try to replicate this on EVM.

-Wenhao

0 user803572 over 3 years ago in reply to Wenhao Wu

Prodigy 40 points

Hi, Wenhao,

This is because if the system power is turned on again with VOUT floating at 0.15-0.3V, the downstream power supply will malfunction.

The floating of VOUT is 0.05 to 0.15V at Ta = 25 ℃, but increases from 0.2 to 0.35V at 55 ℃ or higher.

0 Wenhao Wu over 3 years ago in reply to user803572

TI__Genius 9046 points

Hi Sir,

Well noted. I replicated the same thing on EVM and let me check this out internally. Just curious, do you know which load can work under such a low voltage?

-Wenhao

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TPS61252: Leakage current from VIN to VOUT & VF