Small-signal model-based design of digital current-mode control

Based on a small-signal model of the power converters, a digital current-mode controller for power converter applications is designed. The model-based derivation of the control law results in the designed controller being applicable to three basic types of converters; (i) boost; (ii) buck; and (iii) buck-boost converters. The designed digital current-mode controller exhibits a fast current response to changes in a reference signal without the instability problem normally observed in converter applications that use a conventional analog-type current-mode controller. Simulations and experiments are presented to show the usefulness of the designed controller.