TPS61291: The power consumption

Jerry Hsu3

Part Number: TPS61291

Hi Sir,

I am in charge of a IoT project. I plan to use TPS61291 for main power supply.

Just wondering the current consumption, would you please let me know the maximum output current of the following condition :

VIN : 3.0V ~ 3.6V

Vout : 3.8V

over 2 years ago

0 Wenhao Wu over 2 years ago

TI__Genius 9046 points

Hi Jerry,

Are you sure the device is TPS61291? The device VOUT options are only 3.3V, 3V and 2.5V. There is no 3.8V available.

-Wenhao

0 Wenhao Wu over 2 years ago in reply to Wenhao Wu

TI__Genius 9046 points

Hi Jerry,

Could you please let me know your comments? Thanks!

-Wenhao

0 Wenhao Wu over 2 years ago in reply to Wenhao Wu

TI__Genius 9046 points

Hi Jerry,

Since there is no reply from you. I put a general answer that I would use to check max output current:

1.Check the minimum current limit threshold of the device. For TPS61291, it is 700mA;

2.Assume the efficiency of the application case. Check the efficiency curve in datasheet. Typically I would use min Vin for the worst case. So let VIN=1.8V, Vo=3.3V, TPS61291 has average efficiency of 85% for load>1mA;

3.Calculation delta IL: Use 300mA for TPS61291

4.Calculation maximum output current

Imax=(VIN*EFF/VOUT)*(ILIM-150mA)

For VIN=1.8V, VOUT=3.3V, EFF=85%, ILIM=700mA, we have IMAX=255mA.

Another way to check maximum output current is go to datasheet Figure 16. There is a curve over there.

-Wenhao

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TPS61291: The power consumption