IL410/ IL4108

Document Number 83627

Rev. 1.4, 26-Apr-04

Vishay Semiconductors

www.vishay.com

5

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)

Figure 2. Normalized LED Trigger Current vs. Power Factor

Figure 3. Forward Voltage vs. Forward Current

iil410_02

1.2

1.0

0.8

0.6

0.4

0.2

0.0

0.8

1.0

1.2

1.4

1.6

1.8

2.0

PF - Power Factor

Ta = 25°C

IFth Normalized to IFth @ PF = 1.0

iil410_03

100

10

1

.1

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

IF - Forward Current - mA

Ta = -55°C

Ta = 25°C

Ta = 85°C

Figure 4. Peak LED Current vs. Duty Factor, Tau

Figure 5. Maximum LED Power Dissipation

iil410_04

10-6

10-5

10-4

10 -3

10-2

10-1

10 0

101

10

100

1000

10000

t -LED Pulse Duration -s

.005

.05

.02

.01

.1

.2

.5

Duty Factor

t

τ

DF = /t

τ

iil410_05

100

80

60

40

20

0

-20

-40

-60

0

50

100

150

Ta - Ambient Temperature - °C