IL410/ IL4108
Vishay Semiconductors
The hold-off condition also can be eliminated by pro-
viding a higher level of LED drive current. The higher
LED drive provides a larger photocurrent which
causes the phototransistor to turn-on before the com-
mutating spike has activated the zero cross network.
Figure 2 shows the relationship of the LED drive for
power factors of less than 1.0. The curve shows that
if a device requires 1.5 mA for a resistive load, then
1.8 times (2.7 mA) that amount would be required to
control an inductive load whose power factor is less
than 0.3.
Typical Characteristics (Tamb = 25
°C
unless otherwise specified)
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.0
iil410_02
If(pk) - Peak LED Current - mA
IFth Normalized to IFth @ PF = 1.0
Ta = 25°C
10000
Duty Factor
1000
.005
.01
.02
.05
.1
.2
.5
τ
NIFth - Normalized LED
Trigger Current
t
DF =
τ
/t
100
0.2
0.4
0.6
0.8
PF - Power Factor
1.0
1.2
iil410_04
10
10 -6
10 -5
10 -4 10 -3 10 -2 10 -1
t -LED Pulse Duration -s
10 0
101
Figure 2. Normalized LED Trigger Current vs. Power Factor
Figure 4. Peak LED Current vs. Duty Factor, Tau
1.4
1.3
VF - Forward Voltage - V
150
Ta = -55°C
LED - LED Power - mW
1.2
1.1
1.0
0.9
0.8
0.7
.1
1
10
IF - Forward Current - mA
100
Ta = 85°C
Ta = 25°C
100
50
0
-60
iil410_05
-40
iil410_03
-20
0
20
40
60
Ta - Ambient Temperature - °C
80
100
Figure 3. Forward Voltage vs. Forward Current
Figure 5. Maximum LED Power Dissipation
Document Number 83627
Rev. 1.4, 26-Apr-04
www.vishay.com
5
VISHAY [ VISHAY TELEFUNKEN ]
