Transient voltage suppressors are effective protection devices against repetitive and non-repetitive over voltages caused by events like electrostatic discharging or during inductive switching. They have symmetric blocking characteristics with avalanche breakdown capability.
The 5SSA and 5SSB silicon surge voltage suppressors are best suited for power thyristors, transistors and IGBTs (insulated-gate bipolar transistors) against small and medium power surges (eg 200 kW over 10 microseconds). They allow to use thyristors with lower voltage capabilities and much smaller snubber circuits.
5SSA and 5SSB silicon surge voltage suppressors consist of a diffused pnp-Si-wafer mounted with pressure contact in a hermetically sealed metal-ceramic-package.