New Bidirectional Asymmetric High Voltage TVS (Transient Voltage Suppressor) Device

Transient Voltage Suppressor (TVS) diodes are semiconductor devices with a well-defined breakdown voltage. Once this voltage is exceeded, the TVS-diode changes from blocking into conducting mode and thus limits the voltage in a paralleled device, TVS-diodes absorb the energy contained in the over-voltage event to protect power semiconductors from destructive voltage overshoots [1]. A further use is in protecting power semiconductors like IGBTs [2]. Here, the so-called active clamping is used to prevent damage by exceeding tolerable voltage levels. However, to achieve suitably high voltages of 1200 V, several devices need to be connected in series which results in some drawbacks including space consumption, device tolerances and cost. This work presents the design of monolithically integrated bidirectional high-voltage TVS-diode dedicated to the active clamping function.