Optically Coupled 20 mA
Current Loop Transmitter
Technical Data
HCPL-4100
Features
• Guaranteed 20 mA Loop
Parameters
• Data Input Compatible with
LSTTL, TTL and CMOS
Logic
• Guaranteed Performance
over Temperature (0°C to
70°C)
• Internal Shield for High
Common Mode Rejection
• 20 kBaud Data Rate at 400
Metres Line Length
• Guaranteed On and Off
Output Current Levels
• Safety Approval
UL Recognized -2500 V rms for
1 minute
CSA Approved
• Optically Coupled 20 mA
Current Loop Receiver,
HCPL-4200, Also Available
Applications
• Isolated 20 mA Current
Loop Transmitter in:
Computer Peripherals
Industrial Control Equipment
Data Communications
Equipment
Description
The HCPL-4100 optocoupler is
designed to operate as a transmit-
ter in equipment using the 20 mA
current loop. 20 mA current loop
systems conventionally signal a
logic high state by transmitting
20 mA of loop current (MARK),
and signal a logic low state by
allowing no more than a few
milliamperes of loop current
(SPACE). Optical coupling of the
signal from the logic input to the
20 mA current loop breaks
ground loops and provides very
high immunity to common mode
interference.
The HCPL-4100 data input is
compatible with LSTTL, TTL, or
CMOS logic gates. The input
integrated circuit drives a GaAsP
LED. The light emitted by the
LED is sensed by a second inte-
grated circuit that allows 20 mA
to pass with a voltage drop of less
than 2.7 volts when no light is
emitted and allows less than 2 mA
to pass when light is emitted. The
transmitter output is capable of
withstanding 27 volts. The input
integrated circuit provides a
controlled amount of LED drive
current and takes into account
any LED light output degrada-
tion. The internal shield allows a
guaranteed 1000 V/µs common
mode transient immunity.
CAUTION: It is advised that normal static precautions be taken in handling and assembly of this component to
prevent damage and/or degradation which may be induced by ESD.
Functional Diagram
A 0.1 µF bypass capacitor connected between pins 8 and 5 is recommended.
2
Ordering Information
Specify part number followed by Option Number (if desired).
HCPL-4100# XXX
300 = Gull Wing Surface Mount Lead Option
500 = Tape/Reel Package Option (1 K min)
Option data sheets available. Contact your Agilent sales representative or authorized distributor for
information.
Package Outline Drawings
8-Pin DIP Package (HCPL-4100)
9.65 ± 0.25
(0.380 ± 0.010)
1.78 (0.070) MAX.
1.19 (0.047) MAX.
A XXXX
YYWW
DATE CODE
1.080 ± 0.320
(0.043 ± 0.013) 2.54 ± 0.25
(0.100 ± 0.010)
0.51 (0.020) MIN.
0.65 (0.025) MAX.
4.70 (0.185) MAX.
2.92 (0.115) MIN.
DIMENSIONS IN MILLIMETERS AND (INCHES).
5678
4321
5° TYP.
TYPE NUMBER
UL
RECOGNITION
UR
0.254 + 0.076
- 0.051
(0.010+ 0.003)
- 0.002)
7.62 ± 0.25
(0.300 ± 0.010)
6.35 ± 0.25
(0.250 ± 0.010)
3
8-Pin DIP Package with Gull Wing Surface Mount Option 300 (HCPL-4100)
240
∆T = 115°C, 0.3°C/SEC
0
∆T = 100°C, 1.5°C/SEC
∆T = 145°C, 1°C/SEC
TIME – MINUTES
TEMPERATURE – °C
220
200
180
160
140
120
100
80
60
40
20
0
260
123456789101112
Thermal Profile (Option #300)
Figure 1. Maximum Solder Reflow Thermal Profile.
(Note: Use of non-chlorine activated fluxes is recommended.)
0.635 ± 0.25
(0.025 ± 0.010) 12° NOM.
9.65 ± 0.25
(0.380 ± 0.010)
0.635 ± 0.130
(0.025 ± 0.005)
7.62 ± 0.25
(0.300 ± 0.010)
5
6
7
8
4
3
2
1
9.65 ± 0.25
(0.380 ± 0.010)
6.350 ± 0.25
(0.250 ± 0.010)
1.016 (0.040)
1.194 (0.047)
1.194 (0.047)
1.778 (0.070)
9.398 (0.370)
9.906 (0.390)
4.826
(0.190)
TYP.
0.381 (0.015)
0.635 (0.025)
PAD LOCATION (FOR REFERENCE ONLY)
1.080 ± 0.320
(0.043 ± 0.013)
4.19
(0.165)MAX.
1.780
(0.070)
MAX.
1.19
(0.047)
MAX.
2.54
(0.100)
BSC
DIMENSIONS IN MILLIMETERS (INCHES).
LEAD COPLANARITY = 0.10 mm (0.004 INCHES).
0.254 + 0.076
- 0.051
(0.010+ 0.003)
- 0.002)
4
Regulatory Information
The HCPL-4100 has been
approved by the following
organizations:
UL
Recognized under UL 1577,
Component Recognition
Program, File E55361.
CSA
Approved under CSA Component
Acceptance Notice #5, File CA
88324.
Insulation and Safety Related Specifications
Parameter Symbol Value Units Conditions
Min. External Air Gap L(IO1) 7.1 mm Measured from input terminals to output
(External Clearance) terminals, shortest distance through air
Min. External Tracking Path L(IO2) 7.4 mm Measured from input terminals to output
(External Creepage) terminals, shortest distance path along body
Min. Internal Plastic Gap 0.08 mm Through insulation distance, conductor to
(Internal Clearance) conductor, usually the direct distance
between the photoemitter and photodetector
inside the optocoupler cavity
Tracking Resistance CTI 200 Volts DIN IEC 112/VDE 0303 PART 1
(Comparative Tracking Index)
Isolation Group IIIa Material Group (DIN VDE 0110, 1/89, Table 1)
Option 300 – surface mount classification is Class A in accordance with CECC 00802.
Absolute Maximum Ratings
(No Derating Required up to 55°C)
Storage Temperature .................................................. -55°C to +125°C
Operating Temperature ................................................. -40°C to +85°C
Lead Solder Temperature .... 260°C for 10 s (1.6 mm below seating plane)
Supply Voltage – VCC .............................................................. 0 V to 20 V
Average Output Current - IO........................................ -30 mA to 30 mA
Peak Output Current - IO........................................... Internally Limited
Output Voltage – VO........................................................ -0.4 V to 27 V
Input Voltage – VI............................................................ -0.5 V to 20 V
Input Power Dissipation – PI................................................. 265 mW[1]
Output Power Dissipation – PO............................................. 125 mW[2]
Total Power Dissipation – P .................................................. 360 mW[3]
Infrared and Vapor Phase Reflow Temperature
(Option #300) ..........................................see Fig. 1, Thermal Profile
5
Recommended Operating Conditions
Parameter Symbol Min. Max. Units
Power Supply Voltage VCC 4.5 20 Volts
Input Voltage Low VIL 0 0.8 Volts
Input Voltage High VIH 2.0 20 Volts
Operating Temperature TA070 °C
Output Voltage VO0 27 Volts
Output Current IO024 mA
DC Electrical Specifications
For 0°C ≤ T
A ≤ 70°C, 4.5 V ≤ VCC ≤ 20 V, all typicals at TA = 25°C and VCC = 5 V unless otherwise noted.
See note 12.
Parameter Symbol Min. Typ. Max. Units Test Conditions Fig. Note
Mark State Output VMO 1.8 2.25 Volts IO = 2 mA VI = 2.0 V 2, 3
Current 2.2 Volts IO = 12 mA
2.35 2.7 Volts IO = 20 mA
Mark State Short ISC 30 85 mA VI = 2 V, VO = 5 V to 27 V 4
Circuit Output
Current
Space State Input ISO 0.5 1.1 2.0 mA VI = 0.8 V, VO = 27 V 4
Current
Low Level Input IIL -0.12 -0.32 mA VCC = 20 V, VI = 0.4 V
Current
Low Level Input VIL 0.8 Volts
Voltage
High Level Input VIH 2.0 Volts
Voltage
High Level Input IIH 20 µAV
I
= 2.7 V
Current 100 µAV
I
= 5.5 V
0.005 250 µAV
I
= 20 V
Supply Current ICC 7.0 11.5 mA VCC = 5.5 V 0 V ≤ VI ≤ 20 V
7.8 13 mA VCC = 20 V
6
Switching Specifications
For 0°C ≤ T
A ≤ 70°C, 4.5 V ≤ VCC ≤ 20 V, all typicals at TA = 25°C and VCC = 5 V unless otherwise noted.
See note 12.
Parameter Symbol Min. Typ. Max. Units Test Conditions Fig. Note
Propagation Delay Time tPLH 0.3 1.6 µsC
O
= 1000 pF, 5, 6, 6
to Logic High Output Level CL = 15 pF, 7
IO = 20 mA
Propagation Delay Time tPHL 0.2 1.0 µsC
O
= 1000 pF, 5, 6, 7
to Logic Low Output Level CL = 15 pF, 7
IO = 20 mA
Propagation Delay Time tPLH - tPHL 0.1 µsI
O
= 20 mA
Skew
Output Rise Time tr16 ns IO = 20 mA, 6, 8 8
(10-90%) CO = 1000 pF,
CL = 15 pF
Output Fall Time tf23 ns IO = 20 mA, 6, 8 9
(90-10%) CO = 1000 pF,
CL = 15 pF
Common Mode Transient |CMH| 1,000 10,000 V/µsV
I
= 2 V, 9, 10 10
Immunity at Logic High TA = 25°C
Output Level V
CM = 50 V (peak),
VCC = 5 V
IO (min.) = 12 mA
Common Mode Transient |CML| 1,000 10,000 V/µsV
I
= 0.8 V, 9, 10 11
Immunity at Logic Low TA = 25°C
Output Level V
CM = 50 V (peak),
VCC = 5 V
IO (max.) = 3 mA
Package Characteristics
For 0°C ≤ TA ≤ 70°C, unless otherwise specified. All typicals at TA = 25°C.
Parameter Symbol Min. Typ. Max. Units Test Conditions Fig. Notes
Input-Output Momentary VISO 2500 V rms RH ≤ 50%, t = 1 min,
Withstand Voltage* TA = 25°C 5, 13
Resistance, Input-Output RI-O 1012 ohms VI-O = 500 V dc 5
Capacitance, Input-Output CI-O 1 pF f = 1 MHz,
VI-O = 0 V dc 5
*The Input-Output Momentary Withstand Voltage is a dielectric voltage rating that should not be interpreted as an input-output
continuous voltage rating. For the continuous voltage rating refer to the VDE 0884 Insulation Characteristics Table (if applicable),
your equipment level safety specification, or Agilent Application Note 1074, “Optocoupler Input-Output Endurance Voltage.”
7
Notes:
1. Derate linearly above 55 °C free air
temperature at a rate of 3.8 mW/ °C.
Proper application of the derating
factors will prevent IC junction
temperatures from exceeding 125 °C
for ambient temperatures up to 85 °C.
2. Derate linearly above a free-air
temperature of 70 °C at a rate of 2.3
mW/ °C. A significant amount of
power may be dissipated in the
HCPL-4100 output circuit during the
transition from the SPACE state to
the MARK state when driving a data
line or capacitive load (C OUT). The
average power dissipation during the
transition can be estimated from the
following equation which assumes a
linear discharge of a capacitive load:
P = ISC (VSO + VMO)/2, where VSO is
the output voltage in the SPACE
state. The duration of this transition
can be estimated as t = C OUT (VSO -
VMO)/ISC. For typical applications
driving twisted pair data lines with
NRZ data as shown in Figure 11, the
transition time will be less than 10%
of one bit time.
3. Derate linearly above 55 °C free-air
temperature at a rate of 5.1 mW/ °C.
4. The maximum current that will flow
into the output in the mark state (I SC)
is internally limited to protect the
device. The duration of the output
short circuit shall not exceed 10 ms.
5. The device is considered a two
terminal device, pins 1, 2, 3, and 4
are connected together, and pins 5,
6, 7, and 8 are connected together.
6. The tPLH propagation delay is
measured from the 1.3 volt level on
the leading edge of the input pulse to
the 10 mA level on the leading edge
of the output pulse.
7. The tPHL propagation delay is
measured from the 1.3 volt level on
the trailing edge of the input pulse to
the 10 mA level on the trailing edge
of the output pulse.
8. The rise time, t r, is measured from the
10% to the 90% level on the rising
edge of the output current pulse.
9. The fall time, t f, is measured from the
90% to the 10% level on the falling
edge of the output current pulse.
10. Common mode transient immunity in
the logic high level is the maximum
(positive) dVCM/dt on the leading
edge of the common mode pulse,
VCM, that can be sustained with the
output in a Mark ("H") state (i.e.,
IO> 12 mA).
11. Common mode transient immunity in
the logic low level is the maximum
(positive) dVCM/dt on the leading
edge of the common mode pulse,
VCM, that can be sustained with the
output in a Space ("L") state (i.e., IO
< 3 mA).
12. Use of a 0.1 µF bypass capacitor
connected between pins 5 and 8 is
recommended.
13. In accordance with UL 1577, each
optocoupler is momentary withstand
proof tested by applying an insulation
test voltage ≥ 3000 V rms for 1
second (leakage detection current
limit, Ii-o ≤ 5 µA).
Figure 2. Typical Mark State Output
Voltage vs. Temperature. Figure 3. Typical Output Voltage vs.
Loop Current.
Figure 4. Typical Space State Output
Current vs. Temperature.
V
O
– OUTPUT VOLTAGE – V
-40
1.6
1.2
T
A
– TEMPERATURE – °C
060
1.8
1.4
-20 20 40
2.0
2.2
2.4
2.6
2.8
3.0
80 100
I
O
20 mA
12 mA
2 mA
V
CC
= 5 V
V
I
= 2 V
V
O
– OUTPUT VOLTAGE – V
0
1.0
0
I
O
– OUTPUT CURRENT – mA
10 20
1.5
0.5
515
2.0
2.5
3.0
3.5
25 30
V
CC
= 5 V
V
I
= 2 V
T
A
= 25 °C
I
S
– SPACE CURRENT – mA
-40
0.8
0.6
T
A
– TEMPERATURE – °C
060
0.9
0.7
-20 20 40
1.0
1.1
1.2
1.3
80 100
V
O
27 V
20 V
V
CC
= 5 V
V
I
= 0.8 V
8
t
p
– PROPAGATION DELAY – µs
-40
0.2
0
T
A
– TEMPERATURE – °C
060
0.3
0.1
-20 20 40
0.4
0.5
0.6
80 100
t
PLH
C
O
= 1000 pF
C
L
= 15 pF
V
CC
= 5 V
I
O
= 20 mA
t
PHL
Figure 5. Test Circuit for tPLH, tPHL,
tr, and tf.Figure 6. Waveforms for tPLH, tPHL, tr, and tf.
Figure 7. Typical Propagation Delay
vs. Temperature. Figure 8. Typical Rise, Fall Times vs.
Temperature.
t
r
, t
f
– RISE AND FALL TIMES – ns
-40
20
0
T
A
– TEMPERATURE – °C
060
30
10
-20 20 40
40
50
60
70
80 100
t
f
V
CC
= 5 V
C
OUT
= 1000 pF
C
L
= 15 pF
I
O
= 20 mA
t
r
Figure 9. Test Circuit for Common
Mode Transient Immunity. Figure 10. Typical Waveforms for
Common Mode Transient Immunity.
9
Applications
Data transfer between equipment
which employs current loop
circuits can be accomplished via
one of three configurations:
simplex, half duplex or full
duplex communication. With
these configurations, point-to-
point and multidrop arrangements
are possible. The appropriate
configuration to use depends
upon data rate, number of
stations, number and length of
lines, direction of data flow,
protocol, current source location
and voltage compliance value,
etc.
Simplex
The simplex configuration,
whether point to point or multi-
drop, gives unidirectional data
flow from transmitter to trans-
mitter(s). This is the simplest
configuration for use in long line
length (two wire), moderate data
rate, and low current source
compliance level applications. A
block diagram of simplex point to
point arrangement is given in
Figure 11 for the HCPL-4100
transmitter optocoupler.
Major factors which limit maxi-
mum data rate performance for a
simplex loop are the location and
compliance voltage of the loop
current source as well as the total
line capacitance. Application of
the HCPL-4100 transmitter in a
simplex loop necessitates thtat a
non-isolated active receiver
(containing current source) be
used at the opposite end of the
current loop. With long line
length, large line capacitance will
need to be charged to the
compliance voltage level of the
current source before the
receiver loop current decreases
to zero. This effect limits upper
data rate performance. Slower
data rates will occur with larger
compliance voltage levels. The
maximum compliance level is
determined by the transmitter
breakdown characteristic. In
addition, adequate compliance of
the current source must be
available for voltage drops across
station(s) during the MARK state
in multidrop applications for long
line lengths.
In a simplex multidrop applica-
tion with multiple HCPL-4100
transmitters and one non-isolated
active receiver, priority of
transmitters must be established.
A recommended non-isolated
active receiver circuit which can
be used with the HCPL-4100 in
point-to-point or in multidrop 20
mA current loop applications is
given in Figure 12. This non-
isolated active receiver current
threshold must be chosen
properly in order to provide
adequate noise immunity as well
as not to detect SPACE state
current (bias current) of the
HCPL-4100 transmitter. The
receiver input threshold current
is Vth/Rth ≈ 10 mA. A simple
transistor current source provides
a nominal 20 mA loop current
over a VCC compliance range of 6
V dc to 27 V dc. A resistor can be
used in place of the constant
current source for simple
applications where the wire loop
distance and number of stations
on the loop are fixed. A minimum
transmitter output load capac-
itance of 1000 pF is required
between pins 3 and 4 to ensure
absolute stability.
Length of current loop (one
direction) versus minimum
required DC supply voltage, VCC,
of the circuit in Figure 12 is
graphically illustrated in Figure
13. Multidrop configurations will
require larger VCC than Figure 13
predicts in order to account for
additional station terminal
voltage drops.
Typical data rate performance
versus distance is illustrated in
Figure 14 for the combination of
a non-isolated active receiver and
HCPL-4100 optically coupled
current loop transmitter shown in
Figure 12. Curves are shown for
Figure 11. Simplex Point to Point Current Loop System Configuration.
10
Figure 12. Recommended Non-Isolated Active Receiver with HCPL-4100 Isolated Transmitter for Simplex Point to Point
20 mA Current Loop.
25% distortion data rate at
different VCC values. 25%
distortion data rate is defined as
that rate at which 25% distortion
occurs to output bit interval with
respect to the input bit interval.
Maximum data rate (dotted line)
is restricted by device character-
istics. An input Non-Return-to-
Zero (NRZ) test waveform of 16
bits (0000001011111101) was
used for data rate distortion
measurements. Enhanced speed
performance of the loop system
can be obtained with lower VCC
supply levels, as illustrated in
Figure 14. In addition, when loop
current is supplied through a
resistor instead of by a current
source, an additional series
termination resistance equal to
the characteristic line impedance
can be used at the HCPL-4100
transmitter end to enhance speed
of response by approximately
20%.
The cable used contained five
pairs of unshielded, twisted, 22
AWG wire (Dearborn #862205).
Loop current is 20 mA nominal.
Input and output logic supply
voltages are 5 V dc.
Full Duplex
The full duplex point-to-point
communication of Figure 15 uses
a four wire system to provide
simultaneous, bidirectional data
communication between local
and remote equipment. The basic
application uses two simplex
point-to-point loops which have
two separate, active, non-isolated
units at one common end of the
loops. The other end of each loop
is isolated.
Figure 13. Minimum Required Supply
Voltage, VCC, vs. Loop Length for
Current Loop Circuit of Figure 13.
Figure 14. Typical Data Rate vs.
Distance and Supply Voltage.
V
CC
– VOLTS
0
12
0
L – LOOP LENGTH (ONE DIRECTION) METERS
100 1000
16
4
28
32
36
40
10000
m
V
CC
= 0.00212 — (L) + 5.7 V
R
CABLE
= 0.05296 Ω/m
I
LOOP
= 20 mA
V
MARK
= 2.7 Vdc (HCPL-4100)
V
SAT
= 1.5 Vdc (CURRENT SOURCE)
T
A
= 25 °C
V
24
20
8
11
As Figure 15 illustrates, the
combination of Agilent current
loop optocouplers, HCPL-4100
transmitter and HCPL-4200
receiver, can be used at the
isolated end of current loops.
Cross talk and common mode
coupling are greatly reduced
when optical isolation is imple-
mented at the same end of both
loops, as shown. Full duplex data
rate is limited by the non-isolated
active transmitter current loop.
Comments mentioned under
simplex configuration apply to
the full duplex case. Consult the
HCPL-4200 receiver optocoupler
data sheet for specified device
performance.
Half Duplex
The half duplex configuration,
whether point to point or multi-
drop, gives non-simultaneous
bidirectional data flow from
transmitters to transmitters
shown in Figures 16a and 16b.
This configuration allows the use
of two wires to carry data back
and forth between local and
remote units. However, protocol
must be used to determine which
specific transmitter can operate
at any given time. Maximum data
rate for a half duplex system is
limited by the loop current
charging time. These considera-
tions were explained in the
Simplex configuration section.
Figures 16a and 16b illustrate
half duplex application for the
combination of HCPL-4100/-4200
optocouplers. The unique and
complementary designs of the
HCPL-4100 transmitter and
HCPL-4200 receiver optocoup-
lers provide many designed-in
benefits. For example, total
optical isolation at one end of the
current loop is easily accom-
plished, which results in
substantial removal of common
mode influences, elimination of
ground potential differences and
reduction of power supply
requirements. With this combina-
tion of HCPL-4100/-4200 opto-
couplers, specific current loop
noise immunity is provided, i.e.,
minimum SPACE state current
noise immunity is 1 mA, MARK
state noise immunity is 8 mA.
Voltage compliance of the current
source must be of an adequate
level for operating all units in the
loop while not exceeding 27 V dc,
the maximum breakdown voltage
for the HCPL-4100. Note that the
HCPL-4100 transmitter will allow
output loop current to conduct
when input VCC power is off.
Consult the HCPL-4200 receiver
optocoupler data sheet for
specified device performance.
For more information about the
HCPL-4100/-4200 optocouplers,
consult Application Note 1018.
Figure 15. Full Duplex Point to Point Current Loop System Configuration.
Figure 16. Half Duplex Current Loop System Configurations
for (a) Point to Point, (b) Multidrop.
www.semiconductor.agilent.com
Data subject to change.
Copyright © 1999 Agilent Technologies
Obsoletes 5954-8481
5965-3581E (11/99)
