Abstract:
Background Reverse blocking diode thyristors (RBDTs) are attractive solid-state switches for pulsed power systems because of their high blocking capability and high di/dt turn-on potential. In practical DSRD-triggered operation, the rising-edge voltage slew rate (dv/dt) of the trigger pulse is a key waveform parameter that can alter the initial carrier injection and regenerative turn-on process, and therefore affects the switching transient and current build-up.
Purpose This work aims to quantify how the output dv/dt of a silicon-based drift step recovery diode (Si DSRD) influences the turn-on characteristics of an RBDT, and to identify the dv/dt range where further increase brings diminishing improvement under a fixed pulsed power circuit configuration.
Methods A numerical analysis model of an Si DSRD-triggered RBDT was established by combining TCAD device simulation with an equivalent external circuit. In the simulations, the trigger pulse parameters other than the rising-edge dv/dt were kept constant to isolate the dv/dt effect, and the RBDT turn-on delay time, current rise time, and peak current were evaluated for multiple dv/dt conditions. An Si DSRD-based trigger circuit was then built for experimental verification. Different dv/dt levels were obtained by adjusting trigger-circuit parameters (including the pulse transformer core and turns as well as the shaping capacitor), and the trigger voltage across the RBDT and the corresponding current waveforms were measured to extract the same turn-on metrics.
Results Both simulation and experiment show that increasing the Si DSRD output dv/dt shortens the RBDT turn-on delay time and current rise time, while the peak current exhibits a slight increase under the tested circuit parameters. When dv/dt is raised beyond a certain range, the reductions in delay and rise time become progressively smaller and tend to saturate, indicating diminishing sensitivity of the turn-on transient to further dv/dt enhancement. The overall trends obtained from TCAD and measurements are consistent across the investigated dv/dt range.
Conclusions The voltage rise rate of the Si DSRD trigger waveform is an effective control parameter for tailoring the RBDT turn-on transient, mainly reflected in reduced delay and faster current build-up, with a saturation tendency at higher dv/dt. The reported TCAD–experiment comparison provides a practical basis for selecting dv/dt levels and designing Si DSRD-based trigger conditions for RBDT switching in pulsed power applications.