Digital Control for Efficient Switching Over a Wide Range of Supply Voltages

Abstract:
One way to achieve high power density in a power converter is by using a microcontroller and digitally controlled feedback loops to address some technical performance values. This paper establishes the automatic zero voltage switching (ZVS) operation in order to reduce turn-on losses on 650V GaN power transistor and maintain the temperature within acceptable range without heatsink. The algorithm presented in this paper is tested on a demo board for different values of Vdc bus voltage from 100 V up to 500 V. This paper presents the algorithm and one solution of using one analog-to-digital converter (ADC) inside the microcontroller ST32G4 to read the VDC bus voltage and calculate the deadtime to keep precise ZVS conditions.