TPS92692-Q1: TPS92692-Q1 Buck Boost topology or Boost to battery?

Hello,

1.) what is the function of Q2 PNP transistor in the application circuit shown in datasheet? how to select it?

- In this configuration, Q2 PNP will trigger under-voltage protection if the battery voltage drops below the configured voltage and it will trigger over-voltage protection if the boost converter surpasses the configured voltage

-To select the right transistor, please find one that is close to double your expected output voltage requirements

2.) How is boost to battery and Buck boost topology different? Is there an excel sheet available to calculate for boost to battery?

-Boost to Battery and Buck-Boost topologies are essentially the same. However the key difference is that the Boost to Battery converter is referenced to the battery as shown in the diagram above.

-The excel sheet for Buck-Boost can be used to also calculate Boost to Battery .

3.)Cout value obtained in "buck boost " excel design calculation sheet is connected between LED+ and GND or LED+ and LED- ?

-The Cout value obtained in the excel design calculation will be connected between LED+ and LED-

Hope this helps!