Non-linear control for energy efficient DC-DC converters supporting DCM operation

Non-linear control is a popular way to regulate the output voltage of switch-mode DC-DC converters. In this paper, a controller based on the non-linear sliding mode theory, but adapted to maintain a constant switching frequency, is proposed. A general definition of the sliding surface is suggested, making it possible to use the same control architecture for different DC-DC converter topologies (e.g. Buck, Boost, Buck-Boost). Moreover, the proposed controller supports the discontinuous conducting mode (DCM) to increase the efficiency of the energy conversion under light loads. Several simulation results are presented in order to prove the performance of the controller. A real-world commercial application, i.e. an efficient power supply for mobile devices, has been used as a reference to accurately choose the simulation parameters.