Design Considerations and Comparison between Two High-Frequency Resonant Drivers for Synchronous Rectification MOSFETs

Driving synchronous rectifier (SR) MOSFETs in high-frequency applications requires the ability to supply high total gate charge in a very short time, while maintaining high efficiency. In this paper two resonant drivers are considered with the aim of highlighting merits and limitations of both solutions with focus on high frequency applications: detailed loss analysis has been performed, taking into account all major device parasitics, and suitable design considerations are given. Both drivers have been tested on the same capacitive load showing that, in one case, the switch internal parasitic inductance can adversely affect the circuit behavior, making that topology less suitable for high frequency operation. The more performing resonant driver, was also tested on the Voltage Regulator Module working at 1.8MHz reported in [2].