Four Switch Buck-Boost Converter
A buck-boost converter is an inductor based switching regulator whose output voltage can be lower or higher than the input voltage.
Besides the implementation in this schematic, another topology called inverting buck-boost converter
\[V_{OUT} = \frac{-D}{\frac{R_L}{R*(1-D)}+1-D} * V_{IN}\]Notes: https://www.ti.com/tool/PMP5026