Microcontroller based closed control-loop of an Interleaved Synchronous Buck Converter exploiting Monolithic GaN technology

Mild-hybrid market requires smart and flexible power conversion systems that dynamically adapt their behaviour according to the working conditions and operational needs. This sector also asks for high-efficient converters with limited dimension and weight. Optimal versatility and high power density can be achieved thanks to monolithic GaN technology. In this context, this paper presents a 48-12V interleaved conversion system based on the emerging GaN technology combined with a closed-loop control implemented using the STM32 microcontroller. The main feature of the proposed system is the dynamic closed-loop control implemented by the microcontroller that modulates the driving signals for the interleaved power stages at different load conditions. The microcontroller also introduces the important feature of overcurrent protection to increase the security level of the whole system and react in case of failure. The proposed system combines the improved switching behavior of the GaN compared to silicon and the interleaved synchronous structure to obtain 95% peak efficiency.