Fast-Switching Thyristors Provide Enhanced dv/dt Performance
Littelfuse introduced the EV Series Enhanced Version Teccor brand Thyristors. They feature a minimum rated blocking voltage (Vdrm/Vrrm) of up to 800V, a maximum turn-on time (tq) as low as 25 µs, and a minimum rated static dv/dt of up to 75 V/µs. The high blocking voltage and dv/dt immunity are suited to designers creating circuits for high-stress and/or high-reliability applications. These features help a triac to better survive transient voltages, minimize false triggering, and prevent unstable activation. For example, one of the more common failure mechanisms in thyristors is a permanent short caused by a transient that exceeds the dv/dt rating. This feature helps prevent excess energy from being passed to the circuit or load being protected. Fast turn-on time is important in applications such as ground fault circuit interruption, where it helps ensure proper operation of the associated electromechanical breaker. The switching characteristics of the EV Series also minimize the need for extra components for circuit protection. Designers can now eliminate snubber circuits in many applications. Suggested applications include fault detection circuits, such as ground fault circuit interrupt (GFCI), arc fault circuit interrupt (AFCI), appliance leakage current interrupt (ALCI) and leakage current detection interrupt (LCDI). The 0.8A families are suitable for most applications, while the 1.5A families are for applications with higher current and/or thermal demands.