5–1
NE
W
FEATURES
• Guranteed CTR Symmetry, 2:1 Maximum
• Bidirectional AC Input
Industry Standard SOIC-8 Surface
• Mountable Package
• Standard Lead Spacing, .05"
• Available in Tape and Reel Option
(Conforms to EIA Standard RS481A)
DESCRIPTION
The IL256A is an AC input phototransistor optocou-
pler. The device consists of two infrared emitters
connected in anti-parallel and coupled to a silicon
NPN phototransistor detector.
These circuit elements are constructed with a stan-
dard SOIC-8 foot print.
The product is well suited for telecom applications
such as ring detection or off/on hook status, given
its bidirectional LED input and guaranteed current
transfer ratio (CTR) minimum of 20% at I
F
= 10 mA.
Maximum Ratings
Emitter
Continuous Forward Current.........................60 mA
Power Dissipation at 25
°
C........................... 90 mW
Derate Linearly from 25
°
C..................... 0.8 mW/
°
C
Detector
Collector-Emitter Breakdown Voltage.............. 30 V
Emitter-Collector Breakdown Voltage................ 5 V
Collector-Base Breakdown Voltage................. 70 V
Power Dissipation ..................................... 150 mW
Derate Linearly from 25
°
C..................... 2.0 mW/
°
C
Package
Total Package Dissipation at 25
°
C Ambient
(LED + Detector).................................... 240 mW
Derate Linearly from 25
°
C..................... 3.1 mW/
°
C
Storage Temperature .................. –55
°
C to +150
°
C
Operating Temperature ............... –55
°
C to +100
°
C
Soldering Time at 260
°
C..............................10 sec.
Characteristics
(T
A
=25
°
C)
Sym-
bol Min. Typ. Max. Unit Condition
Emitter
Forward Voltage V
F
1.2 1.5 V I
F
=
±
10 mA
Detector
Breakdown Voltage
Collector-Emitter
Emitter-Collector
Collector Base
BV
CEO
BV
ECO
BV
CBO
30
5
70
50
10
90
V
V
V
I
C
=1 mA
I
E
=100
µ
A
I
C
=100
µ
A
Leakage Current,
Collector-Emitter I
CEO
550nA V
CE
=10 V
Package
DC Current Transfer
Ratio CTR 20 % I
F
=
±
10 mA,
V
CE
=5 V
Symmetry
CTR at +10mA
CTR at –10 mA
0.5 1.0 2.0
Saturation Voltage,
Collector-Emitter V
CEsat
0.4 I
F
=
±
16 mA,
I
C
=2 mA
Isolation Voltage,
Input to Output V
IO
2500 VAC
RMS
Dimensions in inches (mm)
40°
.240
(
6.10)
.154±.005
(3.91±.13)
.050 (1.27)
typ.
.016 (.41)
.192±.005
(4.88±.13)
.004 (.10)
.008 (.20)
Lead
Coplanarity
±.0015 (.04)
max.
.015±.002
(.38±.05)
.008 (.20)
7°
.058±.005
(1.49±.13)
.125±.005
(3.18±.13)
Pin One ID
.120±.005
(3.05±.13) C
L
.021 (.53)
5° max.
R.010
(.25) max.
.020±.004
(.15±.10)
2 plcs.
1
2
3
4
8
7
6
5
NC
Base
Collector
Emitter
Anode/
Cathode
Cathode/
Anode
NC
NC
IL256A
AC INPUT PHOTOTRANSISTOR
SMALL OUTLINE
SURFACE MOUNT OPTOCOUPLER
5–2
IL256A
Figure 1. LED forward current versus forward voltage
Figure 2. Forward voltage versus forward current
Figure 3. Peak LED current versus duty factor, Tau
Figure 4. Normalized CTR versus If and Ta
-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5
-60
-40
-20
0
20
40
60
25°C
85°C
-55°C
VF - LED Forward Voltage - V
IF - LED Forward Current - mA
.1 1 10 100
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
If - Forward Current - mA
Vf-Forward Voltage - V
Ta = -55°C
Ta = 25°C
Ta = 100°C
10-6 10-5 10-4 10-3 10-2 10-1 10 010 1
10
100
1000
10000
t - LED Pulse Duration - s
If(pk) - Peak LED Current - mA
.005
.05
.02
.01
.1
.2
.5
Duty Factor
t
τ
DF = /t
τ
.1 1 10 100
0.0
0.5
1.0
1.5
2.0
Ta = 25°C
Ta = 50°C
Ta = 70°C
Ta = 100°C
If - LED Current - mA
Normalized CTR
Normalized to :
If = 10 mA, Vce =10V
Ta = 25°C
Figure 5. Normalized saturated CTR
Figure 6. Normalized CTRcb
Figure 7. Photocurrent versus LED current
Figure 8. Base current versus If and HFE
.1 1 10 100
0.0
0.2
0.4
0.6
0.8
1.0 Ta = 25°C
Ta = 50°C
Ta = 70°C
Ta = 100°C
If - LED Current - mA
Normalized CTR
Normalized to:
If = 10 mA. Vce =10V
Ta = 25°C
Vce(sat) = 0.4V
.1 1 10 100
0.0
0.5
1.0
1.5
25°C
50°C
70°C
If - LED Current -mA
Normalized CTRcb
Normalized to:
If=10mA, Ta=25°C
.1 1 10 100
.1
1
10
100
1000
25°C
70°C
If - LED Current - mA
Icb - Photocurrent - µA
1 10 100 1000
100
200
300
400
500
600
700
.1
1
10
100
Ib - Base Current - µA
HFE - Transistor Gain
If- LED Current-mA
Vce=0.4V, Ta=25°C
5–3
IL256A
Figure 11. Base emitter voltage versus base current
Figure 12. Collector-emitter leakage current versus
temperature
0.4 0.5 0.6 0.7 0.8
.001
.01
.1
1
10
100
1000
Vbe - Base Emitter Voltage - V
Ib - Base Current - µA
Ta = 25°C
100806040200-20
10 -2
10 -1
10 0
10 1
10 2
10 3
10 4
10 5
Ta - Ambient Temperature - °C
Iceo - Collector-Emitter - nA
TYPICAL
Vce = 10V
Figure 9. Normalized HFE versus Ib, Ta
Figure 10. Normalized saturated HFE versus Ib
1 10 100 1000
0.4
0.6
0.8
1.0
1.2
NHFE -20°C
NHFE 25°C
NHFE 50°C
NHFE 70°C
Ib - Base Current - µA
Normalized HFE
Normalized to:
Ib = 10µA
Ta = 25°C
Vce = 10V
1 10 100 1000
0.0
0.5
1.0
1.5
Ta = -20°C
Ta =25°C
Ta = 50°C
Ta = 70°C
Ib - Base Current - µA
Normalized Saturated HFE
Normalized to:
HFE at Vce = 10V, Icb = 10µA
Ta = 25°C
Vce(sat) = 0.4V
