High-performance digital replica of analogue peak current mode control for DC-DC converter

A simple and robust digital peak current mode controller is proposed in this study. The controller replicates an analogue peak current mode control in the discrete domain. The inner current loop has negligible delay, which results in a high controller bandwidth. The controller structure allows the compensation slope to be updated in each switching cycle; therefore, the controller can maintain a high bandwidth over a wide range of operating points. The modelling principles of an analogue peak current mode controller are used to model the proposed controller. For experimental verification, the controller is implemented in a field programmable gate array to control a 100 W buck converter. The measured loop gain of the system correlates very well with the modelling results. The achieved controller crossover frequency is similar to 1/10 of the switching frequency which is close to the crossover frequency of analogue peak current mode controllers.