Stability Considerations for Silicon Carbide Field-Effect Transistors

Owing to their very low intrinsic capacitance and on-resistance, silicon carbide FETs have been shown to produce poor dynamics in certain power electronics applications, particularly those based on the half-bridge configuration. This letter catalogs three separate phenomena that are observed in the context of such applications and provides a detailed treatment of the most troublesome of these behaviors: the occurrence of sustained oscillation at switch turn-off. This behavior is analyzed in the context of established oscillator design theory; both simulation and experimental results are shown to verify this analysis; and practical suggestions are made to application designers to manage this behavior.