Application information

ACST1035-8FP

8/13

DocID025321 Rev 2

Figure 18: Resistive load control

– typical diagram

2.2

AC line transient voltage ruggedness

In comparison with standard Triac, which need additional protection components against

surge voltage, this device is self-protected against overvoltage, specified by the new

the low energy spikes, such as the inductive spikes at switchoff, or by switching to the on

state (for less than 10 ms) to dissipate higher energy shocks through the load. This safety

feature works even with high turn-on current ramp-up.

The test circuit of Figure 19 represents the ACST1035-8FP application, and is used to

stress the ACST switch according to the IEC 61000-4-5 standard conditions. With the

additional effect of the load which limits the current, the ACST switch withstands the

voltage spikes up to 2 kV on top of the peak line voltage. The protection is based on an

overvoltage crowbar technology. The ACST1035-8FP folds back safely to the on state as

shown in Figure 20. The ACST1035-8FP recovers its blocking voltage capability after the

surge and the next zero crossing current. Such a non repetitive test can be done at least 10

times on each AC line voltage polarity.