Digital constant on-time controlled Multiple-input buck and buck-boost converters

In this paper, digitally realized constant on-time current-mode controlled multiple-input (MI) buck and MI buck-boost converters are presented. Firstly, the control model for a single-input (SI) converter is discussed. Then, the concept of equivalent-single-input (ESI) converter is defined and applied to the constant on-time controlled MI buck and MI buck-boost converters. In this proposed control, only a central controller is needed to control the MI buck or MI buck-boost converter. Thus, the control design and the circuit realization of MI buck and buck-boost converters are greatly simplified. A double-input (DI) discontinuous conduction mode (DCM) buck-boost converter was built to verify the ESI converter design approach.