Investigation of Reverse Blocking Diode Thyristor Under Microsecond Current Pulse

Switches capable of transferring current with pulsewidth of hundreds of microseconds have widespread application across diverse fields, such as pulse power applications, dc protection, and so on. Reverse blocking diode thyristor (RBDT) features a fast switching speed and high surge current ability, which could be a potential candidate for such areas. However, RBDT is now applied in fields which feature short current pulse, and its current limitation characteristics have not undergone thorough evaluation, impeding the broadening of its application range. In this article, RBDT is investigated under current pulse with width of hundreds of microseconds for the first time. The current limitation model is proposed and the structure coefficient
${K} _{\text {RBDT}}$
is obtained at different widths of current pulse. Two different RBDTs are tested under different working conditions. It turns out the structure coefficient of RBDT with blocking voltage of 1100 V is 100 while
${K} _{\text {RBDT}}$
is 82 for RBDT with blocking voltage of 2200 V. Besides, RBDT can cut off the reverse current before it fails due to its reverse blocking capability. The failure mode of RBDT under current pulse with hundreds of microseconds is proposed and verified by 3-D numerical simulation. The failure region is also observed by thermal infrared microscope which validates the proposed failure mechanism. Finally, the characteristics of RBDT are evaluated for potential applications.