Obsolete Product(s) - Obsolete Product(s)
ACS108-5Sx
4/8
®
HIGH INDUCTIVE SWITCH-OFF OPERATION
At the end of the last conduction half-cycle, the load current reaches the holding current level IH, and the
ACS™ switch turns off. Because of the inductance L of the load, the current flows through the avalanche
diode D and decreases linearly to zero. During this time, the voltage across the switch is limited to the
clamping voltage V
CL
.
The energy stored in the inductance of the load depends on the holding current I
H
and the inductance (up
to 10 H); it can reach about 20 mJ and is dissipated in the clamping section that is especially designed for
that purpose.
AC LINE TRANSIENT VOLTAGE RUGGEDNESS
The ACS108 switch is able to safely withstand the AC line transient voltages either by clamping the low
energy spikes or by breaking over under high energy shocks.
The test circuit in Figure 4 is representative of the final ACS™ application and is also used to stress the
ACS™ switch according to the IEC61000-4-5 standard conditions. Thanks to the load, the ACS™ switch
withstands the voltage spikes up to 2 kV above the peak line voltage. It will break over safely even on resis-
tive load where the turn-on current rise is high as shown in Figure 4. Such non-repetitive testing can be
done 10 times on each AC line voltage polarity.
Fig. 1: Turn-off operation of the ACS108 switch
with an electro valve: waveform of the gate current
IG, pin OUT current I
OUT
& voltage V
OUT
.
Fig. 2: ACS108 switch static characteristic.
T
ime (400µs/div)
I
OUT
(10 mA/div)
V
OUT
(200V/div)
I
H
VCL = 650V
I
H
V
CL
I
OUT
V
OUT
Fig. 3: Overvoltage ruggedness test circuit for resis-
tive and inductive loads according to IEC61000-4-5
standard.
R = 150Ω, L = 5µH, V
PP
= 2kV.
Fig. 4: Current and voltage of the ACS™ during
IEC61000-4-5 standard test with a 150Ω - 10µH
load & V
PP
= 2kV.
Iout (2 A/div)
Vout (200 V/div)
dI/dt = 100 A/µs
RL
R
G
= 220
Ω
V
AC
+V
PP
AC LINE &
SURGE VOLTAGE
GENERATOR
GCOM
OUT
ACSxx
ON
S
D
