ESD diode conduction due to kick-back

AN1172

18/23

To compare the kick-back effect of triacs and ACSs, a special test circuit has been defined.

It consists on turning on the switch with a 10nF capacitor connected directly across the A1-

A2 or OUT-COM terminals. The capacitor is charged at 300 V. Figure 19. and Figure 20.

show the experimental results obtained with such a testing method, for a positive bias

voltage.

reaches 13.5 V with a 65 A/µs dI/dt rate. This is largely above the supply voltage. With the

despite a dI/dt which is twice as big as with the Z0109.

ACS / MCU interface would then be secured even at turn-on at peak mains voltage or on a

short-circuit.

Figure 19.

Kick-back test with ACS402

Figure 20.

Kick-back test with Z0109

triac

Iout (5 A/div)

Vg (5 V/div) 1,5 V

+5 V

-5 V

dI/dt = 110 A/µs

IA2 (5 A/div)

Vg (5 V/div)

13,5 V

+5 V

-5 V

dI/dt = 65 A/µs