In low-power thyristors used in consumer applications, the trigger current needed by the
thyristor is small enough that it can be supplied by ICs without the need for an external
pulse amplifier. In high-power thyristors, the trigger current requirement is purposely kept
high in order to provide noise immunity. In such thyristors the initial peak gate current at
turn-on, such as is shown in Fig. 23-9, may be as large as 3 A and then may drop to about
0.5 A for the duration of the pulse.