TPS544B20: Reduce Standby Power by split supply VDD and VIN

Mitchell

Part Number: TPS544B20

Hi Team,

I'd like to get your feedback on a potential way to reduce the standby power of the TPS544B20. Is it safe for my customer to add a FET or load switch to turn off VDD while VIN is still applied?

The datasheet only mentions the effects to the device's over-current protection feature if VDD is different than VIN, but this is a slightly different scenario.

Thanks,
Mitchell

over 6 years ago

0 JohnTucker over 6 years ago

TI__Guru**** 191445 points

Mitchell

We will look into this next week and get back to you then.

0 JohnTucker over 6 years ago in reply to JohnTucker

TI__Guru**** 191445 points

Mitchell,

We don't have any specific data on this, but it should work. The UVLO function is relative to VDD, so if it is not present, TPS544B20 will not be enabled.

0 Mitchell over 6 years ago in reply to JohnTucker

TI__Expert 4915 points

Hi John,

Thanks for the feedback. This is helpful.

My customer has done some testing on this configuration and found that 1V is present at the VDD node when disconnected with Vin still applied (8V), so we think there must be an internal leakage path. Power dissipation went down drastically and they are able to turn it back on, so it seems to be okay so far. They plan to add a pull down so this leakage doesn’t slowly charge the VDD decoupling capacitor.

Thanks,
Mitchell

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TPS544B20: Reduce Standby Power by split supply VDD and VIN