Editing TRIAC (section)

===Critical di/dt===
A high rate of rise of the current between MT1 and MT2 (in either direction) ''when the device is turning on'' can damage or destroy the TRIAC even if the pulse duration is very short. The reason is that during the commutation, the power dissipation is not uniformly distributed across the device. When switching on, the device starts to conduct current before the conduction finishes to spread across the entire junction. The device typically starts to conduct the current imposed by the external circuitry after some nanoseconds or microseconds but the complete switch on of the whole junction takes a much longer time, so too swift a current rise may cause local hot spots that can permanently damage the TRIAC.

In datasheets, this parameter is usually indicated as <math>\frac{\operatorname{d}i}{\operatorname{d}t}</math> and is typically in the order of the tens of ampere per microsecond.<ref name="ThyristorTheory"/>