BUCK-BOOST

Hello eli, 

I recommend and encourage you to use WEBENCH POWER DESIGNER for your buck-boost power supply: https://webench.ti.com/power-designer/switching-regulator   .

From the parameters you specified, WEBENCH generated 7 different designs for the 2.8VOUT/0.3A supply.  Based on what are most important criteria for this design, you can then click the "Sort by:", compare topologies and parameters, selecting the design that best meets your needs.

If, after this process, you have additional questions, you can post a new E2E thread based on the device and topology you have selected.  And if everything is clear and you find the design best suited for your product, please Reply here and let us know. 

Thanks for using E2E,

~Leonard