TIL300, TIL300A
PRECISION LINEAR OPTOCOUPLER
TAOS018 AUGUST 1999
1
www.taosinc.com
t
t
D
ac or dc Signal Coupling
D
Wide Bandwidth . . . >200 kHz
D
High Transfer-Gain Stability . . .
±
0.005%/
°
C
D
3500 V Peak Isolation
D
Typical Applications
Power-Supply Feedback
Medical-Sensor Isolation
Opto Direct-Access Arrangement (DAA)
Isolated Process-Control Transducers
Description
The TIL300 precision linear optocoupler consists of an infrared LED irradiating an isolated feedback photodiode
and an output photodiode in a bifurcated arrangement. The feedback photodiode captures a percentage of the
flux of the LED that can be used to generate a control signal to regulate the LED drive current. This technique
is used to compensate for the nonlinear time and temperature characteristics of the LED. The output-side
photodiode then produces an output signal that is linearly proportional to the servo-optical flux emitted from the
LED.
A typical application circuit (shown in Figure 1) uses an operational amplifier as the input to drive the LED. The
feedback photodiode sources current through R1, which is connected to the inverting input of the input
operational amplifier. The photocurrent I
P1
assumes a magnitude that satisfies the relationship I
P1
=
V
I
/R1. The
magnitude of the current is directly proportional to the LED current through the feedback transfer gain
K1(V
I
/R1 = K1
×
I
F
). The operational amplifier supplies LED current to produce sufficient photocurrent to keep
the node voltage V
b
equal to node voltage V
a.
_
+
+
I
P2
2V
CC+
2V
CC
V
O
= K3(R2/R1) V
I
2V
CC+
6
5
TIL300
1
2
3
4
R3
1V
CC+
I
F
1V
CC
1V
CC+
P
R1
+
V
I
K2
K1
I
P1
V
a
V
b
P
R2
NOTES: A. K1 is servo current gain, the ratio of the feedback servo photodiode current (I
P1
) to the input LED current (I
F
), i.e. K1 = I
P1
/I
F.
B. K2 is forward gain, the ratio of the output photodiode current (I
P2
) to the input LED current (I
F
), i.e. K2 = I
P2
/I
F
.
C. K3 is transfer gain, the ratio of the forward gain to the servo gain, i.e. K3 = K2/K1.
Figure 1. Typical Application Circuit
The output photodiode is connected to a noninverting voltage follower; R2 is used to develop a voltage from
the photodiode current. The output of the amplifier is V
O
= K2I
F
R2. Overall transfer gain V
O
/V
I
becomes
V
O
/V
I
= (K2I
F
R2/K1I
F
R1). Factoring out the LED forward current I
F
and remembering that K2/K1 = K3, the
overall transfer gain becomes V
O
/V
I
= K3R2/R1. The overall transfer gain, therefore, is shown to be
independent of the LED current.
t
t
Copyright
©
2000, TAOS Inc.
Texas Advanced Optoelectronic Solutions Inc.
800 Jupiter Road, Suite 205
S
Plano, TX 75074
S
(972) 673-0759
1
2
3
4
8
7
6
5
LEDK
LEDA
PDK1
PDA1
NC
NC
PDK2
PDA2
DCS OR P PACKAGE
(TOP VIEW)
NC No internal connection
TIL300, TIL300A
PRECISION LINEAR OPTOCOUPLER
TAOS018 AUGUST 1999
2
www.taosinc.com
t
t
Terminal Functions
TERMINAL
DESCRIPTION
NAME
NO.
DESCRIPTION
LEDK
1
LED cathode
LEDA
2
LED anode
PDK1
3
Photodiode 1 cathode
PDA1
4
Photodiode 1 anode
PDA2
5
Photodiode 2 anode
PDK2
6
Photodiode 2 cathode
NC
7
No internal connection
NC
8
No internal connection
Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted)
Emitter
Continuous total power dissipation (see Note 1)
160 mW
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input LED forward current, I
F
60 mA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge current with pulse duration < 10
µ
s 250
mA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reverse voltage, V
R
5 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reverse current, I
R
10
µ
A
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Detector
Continuous total power dissipation (see Note 2)
50 mW
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reverse voltage, V
R
50 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coupler
Continuous total power dissipation (see Note 3)
210 mW
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
stg
55
°
C to 150
°
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, T
A
55
°
C to 100
°
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input-to-output voltage
3535 Vpeak
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds
260
°
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may
affect device reliability.
NOTES: 1. Derate linearly from 25
°
C at a rate of 2.66 mW/
°
C.
2. Derate linearly from 25
°
C at a rate of 0.66 mW/
°
C.
3. Derate linearly from 25
°
C at a rate of 3.33 mW/
°
C.
TIL300, TIL300A
PRECISION LINEAR OPTOCOUPLER
TAOS018 AUGUST 1999
3
www.taosinc.com
t
t
Electrical Characteristics at T
A
=
25
°
C (unless otherwise noted)
Emitter
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
V
F
LED forward voltage
I
F
= 10 mA
1.25
1.50
V
Temperature coefficient of V
F
2.2
mV/
°
C
I
R
Reverse current
V
R
= 5 V
10
µ
A
t
r
Rise time
I
F
= 10 mA,
I
F
= 2 mA
1
µ
s
t
f
Fall time
I
F
= 10 mA,
I
F
= 2 mA
1
µ
s
C
j
Junction capacitance
V
F
= 0,
f = 1 MHz
15
pF
Detector
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
I
DK
Dark current
V
R
= -15 V,
I
F
= 0
25
nA
Open-circuit voltage
I
F
= 10 mA
0.5
V
I
OS
Short-circuit current limit
I
F
= 10 mA
80
µ
A
C
j
Junction capacitance
V
F
= 0,
f = 1 MHz
12
pF
Coupler, detector bias voltage, V
R
= 15 V
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
K1
Servo current gain
I
F
= 1 mA
0.3%
0.7%
1.5%
K1
Servo-current gain
I
F
= 10 mA
0.5%
1.25%
2%
K2
Forward current gain
I
F
= 1 mA
0.3%
0.7%
1.5%
K2
Forward current gain
I
F
= 10 mA
0.5%
1.25%
2%
TIL300
I
F
= 1 mA
0.75
1
1.25
K3
§
Transfer gain
TIL300
I
F
= 10 mA
0.75
1
1.25
K3
§
Transfer gain
TIL300A
I
F
= 1 mA
0.9
1
1.10
TIL300A
I
F
= 10 mA
0.9
1
1.10
Gain temperature coefficient
K1/K2
I
10 mA
0.5
%/
°
C
Gain temperature coefficient
K3
I
F
= 10 mA
±
0.005
%/
°
C
K3
¶
Transfer gain linearity
I
F
= 1 to 10 mA
±
0.25%
K3
¶
Transfer gain linearity
I
F
= 1 to 10 mA,
T
A
= 0 to 75
°
C
±
0.5%
BW
Bandwidth
I
F
= 10 mA,
I
F(MODULATION)
=
±
2 mA
R
L
= 1 k
,
200
kHz
t
r
Rise time
I
F
= 10 mA,
I
F(MODULATION)
=
±
2 mA
R
L
= 1 k
,
1.75
µ
s
t
f
Fall time
I
F
= 10 mA,
I
F(MODULATION)
=
±
2 mA
R
L
= 1 k
,
1.75
µ
s
V
iso
#
Peak isolation voltage
I
IO
= 10
µ
A,
f = 60 Hz,
time = 1 minute
3535
V
Servo-current gain (K1) is the ratio of the feedback photodiode current (I
P1
) to the input LED current (I
F
) current (I
F
), i.e. K1 = I
P1
/I
F
.
Forward gain (K2 is the ratio of the output photodiode current (I
P2
) to the input LED current (I
F
), i.e. K2 = I
P2
/I
F
.
§
Transfer gain (K3) is the ratio of the forward gain to the servo-current gain, i.e. K3 = K2/K1.
¶
Transfer gain linearity
(
K3) is the percent deviation of the transfer gain K3 as a function of LED input current (I
F
) or the package temperature.
#
This symbol is not currently listed within EIA or JEDEC standards for semiconductor symbology.
TIL300, TIL300A
PRECISION LINEAR OPTOCOUPLER
TAOS018 AUGUST 1999
4
www.taosinc.com
t
t
TYPICAL CHARACTERISTICS
Table of Graphs
FIGURE
I
LED Forward Current
vs LED Forward Voltage
2
I
F
LED Forward Current
vs LED Forward Voltage
3
I
Servo Photodiode Current
vs LED Forward Current and Temperature
4
I
p1
Servo Photodiode Current
vs LED Forward Current and Temperature
5
I
Normalized Servo Photodiode Current
vs LED Forward Current and Temperature
6
I
p1
Normalized Servo Photodiode Current
vs LED Forward Current and Temperature
7
K1
Normalized Servo Current Gain
vs LED Forward Current and Temperature
8
K3
Normalized Transfer Gain
vs LED Forward Current
9
A
O
Output Current Amplitude
vs Frequency
10
TIL300, TIL300A
PRECISION LINEAR OPTOCOUPLER
TAOS018 AUGUST 1999
5
www.taosinc.com
t
t
TYPICAL CHARACTERISTICS
Figure 2
15
10
5
0
1
1.1
1.2
1.3
LED Forward Current mA
20
25
LED FORWARD CURRENT
vs
LED FORWARD VOLTAGE
30
1.4
1.5
1.6
V
F
LED Forward Voltage V
T
A
= 25
°
C
I F
1
0.1
1
1.1
1.2
1.3
1.4
10
LED FORWARD CURRENT
vs
LED FORWARD VOLTAGE
100
1.5
V
F
LED Forward Voltage V
LED Forward Current mA
I F
T
A
= 25
°
C
1.6
Figure 3
250
200
100
0
0.1
1
350
450
SERVO PHOTODIODE CURRENT
vs
LED FORWARD CURRENT AND TEMPERATURE
500
10
100
400
300
150
50
T
A
= 75
°
C
T
A
= 0
°
C
T
A
= 50
°
C
T
A
= 25
°
C
Servo Photodiode Current
I
F
LED Forward Current mA
I p1
A
µ
Figure 4
Figure 5
0.1 0.2
0.4 0.7 1
2
4
200
SERVO PHOTODIODE CURRENT
vs
LED FORWARD CURRENT AND TEMPERATURE
1000
10
40 70 1000
700
400
20
100
70
40
2
10
7
4
1
7
20
T
A
= 75
°
C
T
A
= 0
°
C
T
A
= 50
°
C
T
A
= 25
°
C
I
F
LED Forward Current mA
Servo Photodiode Current
I p1
A
µ
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