TPS22908: PTS22908 application question

Dane Zhang

Part Number: TPS22908
Other Parts Discussed in Thread: TPS2113A, TPS2115A,

Hi team

As shown in the figure below, there is a project that uses two load switches to select the power supply path. we want to use the original pin Vout as Vin and the original pin Vin as Vout, as shown in the red font in the figure.( control 1.5V or 2.85V power supply by choosing path and witch just to achieve protection)
Please help to confirm whether this connection method is ok and what are the problems?

over 4 years ago

0 Shreyas Dmello over 4 years ago

TI__Mastermind 32650 points

Hi Dane,

I highly recommend using this document to design a system that can power MUX with load switches: https://www.ti.com/lit/an/slva811a/slva811a.pdf

Finally, another option is to use the TPS2113A or TPS2115A series of power MUXes if the 2.85V signal is always present as this integrated chip will save a lot of space.

0 Dane Zhang over 4 years ago in reply to Shreyas Dmello

TI__Expert 7625 points

Hi Demello,

customer now just want to know if there's any issue if they use the tps22908 like this.

I think there's no theoretically issue right?

0 Shreyas Dmello over 4 years ago in reply to Dane Zhang

TI__Mastermind 32650 points

Hi Dane,

I dont think this topology is ideal. In this case, the device is powered though the output and the body diode of the FET. This is not recommended operation for this device since there is no control that blocks the current from flowing through this path even when the device is OFF.

I do not recommend using this topology. Please refer the customer to the linked document for the best way of Power MUXing using load switches and also the TPS2113A and TPS2115A.

Power management

Power management forum

TPS22908: PTS22908 application question