LAUSR

Suppressing parasitic ringing, unwanted oscillation caused by switching, sufficiently and reliably, is of great importance in wide bandgap semiconductor devices. RC-circuits inserted in parallel with switching devices have been widely used to suppress such parasitic ringing in power electronics circuits due to simple configurations. However, short-circuit current would flow through power lines if capacitors are broken. In this article, we show that parasitic ringing can be damped with an external RLC resonator implemented in parallel to a bus bar. The configuration enables the strong magnetic coupling, which results in high ringing suppression effect. Moreover, the external resonator is designed through analogy with passive parity-time (PT) symmetry. In the range of unbroken phase, ringing energy is distributed effectively to the external resonator, and the damping rate is increased by increasing the loss of the external resonator. Our results represent a significant step toward practical applications of passive PT-symmetry.