Digital Average Current-Mode Control Using Current Estimation and Capacitor Charge Balance Principle for DC–DC Converters Operating in DCM

A new digital average current-mode control technique is proposed for dc-dc converters operation in discontinuous conduction mode. In contrast to the regulation of inductor current, this paper focuses on how the suitable charge current is feed to capacitor and load resistor directly. Using the principle of capacitor charge balance, the charge current reference in next switching cycle is predicted in order to drive the output voltage back to its nominal value quickly during transient conditions. The actual average charge current is estimated from a simplified algorithm, which can also be used to calculate the required duty ratio according to the charge current reference. This control technique features good dynamic performance and it is compliant with the performance constraints of digital integrated processor. The effectiveness of the proposed solution has been proved by the simulation and experimental results.