Active Inductor Current Balancing for Interleaving Multi-Phase Buck-Boost Converter

In this paper, active inductor current balancing method for multi-phase four-switch buck-boost converter is presented. The multi-phase four-switch buck-boost converter is proposed for battery powered applications, such as automotive/truck applications, where high power dc-dc converters capable of stepping up and stepping down voltages are required. Inductor current balancing circuit based on the average current sharing bus approach is used to ensure that the inductor currents are evenly distributed. A prototype of 4-phase buck-boost converter was implemented to verify the concept. Experimental results are included to show the inductor current balancing during steady state and load transient.