In this thesis, the possibility of applying digital current mode control on multiple-input (MI) converters is studied. As for MI topologies having a central energy transfer inductor, the predictive constant on-time current-mode control can greatly reduce both the design and digital realization efforts needed. By doing digital constant on-time current-mode control, the control of MI buck and MI buck-boost converters can be simplified into an equivalent-single-input converter control problem. The small signal models of digital constant on-time controlled single-input (SI), MI buck and SI, MI buck-boost converters in both CCM and DCM are proposed. Simulations and experiments were built to verify the proposed models.