Description

This DC-DC power converter reference design demonstrates a novel approach for battery backup applications. During normal operation: the converter works as a battery charger with CC-CV-Topping charging algorithm compatible for lithium-ion batteries. When DC bus power is lost: the converter immediately changes to backup operation to seamlessly provide power to the system. Once the DC bus power recovers: the converter automatically switches back to battery charge mode. The battery voltage can be higher or lower than DC bus voltage. Depending on the DC bus and battery voltage: the converter operates as either a synchronize buck or a synchronize boost converter in which only two switches are switching: switching loss is reduced and high effieciency is achieved. Only when DC bus and battery voltage are close to each other: then the converter operates as a buck-boost converter.