Alternating Control and Optimizing Bandwidth in Buck-Boost Circuits (Download)
H-bridge buck-boost ICs are widely used in applications requiring a constant voltage or current source even when the system battery drops to lower voltages. They make sense when a single-stage converter is desired, and the output can be set above or below the input voltage. They can also be used as current sources for LED applications to simplify the design of typical boost-to-buck conversion into a single stage.
These ICs are often favored over other buck-boost topologies, such as single-ended primary inductor converters (SEPIC), due to the cost of the coupled inductor.