Advanced gate control system for power MOSFET switching losses reduction with complete switching sequence control

Abstract

To meet strict EMC requirements for power electronics applications driving an inductive load, it is often necessary to mitigate current and voltage transition slopes. Using the conventional MOSFET control method, slope mitigation is commonly performed by modifying a series gate resistance, which results in high switching losses, long turn-on and turn-off delays and long final gate charging and discharging durations affecting the overall application efficiency. In order to improve this, a novel MOSFET control method is developed and presented in this paper. It enables a complete control over all intervals of the switching sequences utilizing the gate current shaping principle. Switching losses, delays and final gate charging and discharging durations can be kept as low as possible, as the method allows to mitigate only the critical transition. The design of the system allows its implementation in a broad spectrum of applications regardless of the current or voltage rating and with a minimal impact on the application design. The paper first presents the inductive load switching background, followed by the detailed description of the presented system operation and its realization as an integrated circuit. At the end, efficiency measurements of the conventional and the advanced gate control methods are reported, showing significant advantages of the proposed system.