AVAGO HCNR200-500E High-linearity analog optocoupler Datasheet

HCNR200 and HCNR201
High-Linearity Analog Optocouplers
Data Sheet
Lead (Pb) Free
RoHS 6 fully
compliant
RoHS 6 fully compliant options available;
-xxxE denotes a lead-free product
Description
Features
The HCNR200/201 high-linearity analog optocoupler
consists of a high-performance AlGaAs LED that illuminates two closely matched photodiodes. The input photodiode can be used to monitor, and therefore stabilize,
the light output of the LED. As a result, the non-linearity
and drift characteristics of the LED can be virtually eliminated. The output photodiode produces a photocurrent
that is linearly related to the light output of the LED. The
close matching of the photo-diodes and advanced design of the package ensure the high linearity and stable
gain characteristics of the optocoupler.
 Low nonlinearity: 0.01%
 K3 (IPD2/IPD1) transfer gain
HCNR200: ±15%
HCNR201: ±5%
 Low gain temperature coefficient: -65 ppm/°C
 Wide bandwidth – DC to >1 MHz
 Worldwide safety approval
– UL 1577 recognized (5 kV rms/1 min rating)
– CSA approved
– IEC/EN/DIN EN 60747-5-2 approved
VIORM = 1414 V peak (option #050)
 Surface mount option available (Option #300)
 8-Pin DIP package - 0.400” spacing
 Allows flexible circuit design
The HCNR200/201 can be used to isolate analog signals
in a wide variety of applications that require good stability, linearity, bandwidth and low cost. The HCNR200/201
is very flexible and, by appropriate design of the application circuit, is capable of operating in many different
modes, including: unipolar/bipolar, ac/dc and inverting/
non-inverting. The HCNR200/201 is an excellent solution
for many analog isolation problems.
Schematic
1
8
LED CATHODE
NC
VF
+
LED ANODE
IF
NC
2
7
3
6
PD1 CATHODE
IPD1
Applications
 Low cost analog isolation
 Telecom: Modem, PBX
 Industrial process control:
Transducer isolator
Isolator for thermocouples 4 mA to 20 mA loop isolation
 SMPS feedback loop, SMPS feedforward
 Monitor motor supply voltage
 Medical
PD2 CATHODE
I PD2
PD1 ANODE
PD2 ANODE
4
5
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.
Ordering Information
HCNR200/HCNR201 is UL Recognized with 5000 Vrms for 1 minute per UL1577.
Option
RoHS
non RoHS
Compliant Compliant
Package
-000E
no option
400 mil
-300E
#300
Widebody
X
X
HCNR200
-500E
#500
DIP-8
X
X
HCNR201
-050E
#050
-350E
#350
X
X
-550E
#550
X
X
Part
Number
Surface
Mount
Gull
Wing
Tape
& Reel
X
X
IEC/EN/DIN EN
UL 5000 Vrms/ 60747-5-2
1 Minute rating VIORM = 1414 Vpeak
Quantity
X
42 per tube
X
42 per tube
X
750 per reel
X
X
42 per tube
X
X
42 per tube
X
X
750 per reel
To order, choose a part number from the part number column and combine with the desired option from the option
column to form an order entry.
Example 1:
HCNR200-550E to order product of Gull Wing Surface Mount package in Tape and Reel packaging with IEC/EN/
DIN EN 60747-5-2 VIORM = 1414 Vpeak Safety Approval and UL 5000 Vrms for 1 minute rating and RoHS compliant.
Example 2:
HCNR201 to order product of 8-Pin Widebody DIP package in Tube packaging with UL 5000 Vrms for 1 minute rating
and non RoHS compliant.
Option datasheets are available. Contact your Avago sales representative or authorized distributor for information.
Remarks: The notation ‘#XXX’ is used for existing products, while (new) products launched since July 15, 2001 and
RoHS compliant will use ‘–XXXE.’
2
Package Outline Drawings
0.20 (0.008)
0.30 (0.012)
11.30 (0.445)
MAX.
8
7
6
5
MARKING
A
HCNR200
XXX
yyww
z
*
PIN
ONE
1
2
3
9.00
(0.354)
TYP.
10.16
(0.400)
TYP.
11.00
(0.433)
MAX.
0°
15°
4
1.50
(0.059)
MAX.
1
5.10 (0.201) MAX.
LED
2
0.51 (0.021) MIN.
1.70 (0.067)
1.80 (0.071)
3.10 (0.122)
3.90 (0.154)
0.40 (0.016)
0.56 (0.022)
2.54 (0.100) TYP.
K2
K1
3
4
NC
8
NC
7
6
PD1
PD2
5
DIMENSIONS IN MILLIMETERS AND (INCHES).
MARKING :
XXX = 050 ONLY if option #050,#350,#550 (or -050,-350,-550)
ordered (otherwise blank)
yy
- Year
ww
- Work Week
Marked with black dot - Designates Lead Free option E
*
- Designates pin 1
NOTE: FLOATING LEAD PROTRUSION IS 0.25 mm (10 mils) MAX.
Figure 1a. 8 PIN DIP
3
Gull Wing Surface Mount Option #300
11.15 ± 0.15
(0.442 ± 0.006)
8
7
6
LAND PATTERN RECOMMENDATION
5
9.00 ± 0.15
(0.354 ± 0.006)
1
2
3
13.56
(0.534)
4
1.3
(0.051)
2.29
(0.09)
12.30 ± 0.30
(0.484 ± 0.012)
1.55
(0.061)
MAX.
11.00 MAX.
(0.433)
4.00 MAX.
(0.158)
1.78 ± 0.15
(0.070 ± 0.006)
2.54
(0.100)
BSC
0.75 ± 0.25
(0.030 ± 0.010)
DIMENSIONS IN MILLIMETERS (INCHES).
LEAD COPLANARITY = 0.10 mm (0.004 INCHES).
NOTE: FLOATING LEAD PROTRUSION IS 0.25 mm (10 mils) MAX.
Figure 1b. 8 PIN Gull Wing Surface Mount Option #300
4
1.00 ± 0.15
(0.039 ± 0.006)
+ 0.076
0.254 - 0.0051
+ 0.003)
(0.010 - 0.002)
7° NOM.
Solder Reflow Temperature Profile
300
PREHEATING RATE 3 °C + 1 °C/–0.5 °C/SEC.
REFLOW HEATING RATE 2.5 °C ± 0.5 °C/SEC.
200
PEAK
TEMP.
245 °C
PEAK
TEMP.
240 °C
TEMPERATURE (°C)
2.5 C ± 0.5 °C/SEC.
30
SEC.
160 °C
150 °C
140 °C
SOLDERING
TIME
200 °C
30
SEC.
3 °C + 1 °C/–0.5 °C
100
PEAK
TEMP.
230 °C
PREHEATING TIME
150 °C, 90 + 30 SEC.
50 SEC.
TIGHT
TYPICAL
LOOSE
ROOM
TEMPERATURE
0
50
0
100
150
200
250
TIME (SECONDS)
NOTE: NON-HALIDE FLUX SHOULD BE USED.
Recommended Pb-Free IR Profile
TIME WITHIN 5 °C of ACTUAL PEAK TEMPERATURE
tp
Tp
TEMPERATURE
TL
Tsmax
* 245 +0/-5 °C
15 SEC.
217 °C
150 - 200 °C
RAMP-UP
3 °C/SEC. MAX.
RAMP-DOWN
6 °C/SEC. MAX.
Tsmin
ts
PREHEAT
60 to 180 SEC.
25
tL
60 to 150 SEC.
NOTES:
THE TIME FROM 25 °C to PEAK
TEMPERATURE = 8 MINUTES MAX.
Tsmax = 200 °C, Tsmin = 150 °C
NOTE: NON-HALIDE FLUX SHOULD BE USED.
t 25 °C to PEAK
TIME
Regulatory Information
The HCNR200/201 optocoupler features a 0.400” wide, eight pin DIP package. This package was specifically designed
to meet worldwide regulatory requirements. The HCNR200/201 has been approved by the following organizations:
UL
IEC/EN/DIN EN 60747-5-2
Recognized under UL 1577, Component Recognition
Program, FILE E55361
Approved under
IEC 60747-5-2:1997 + A1:2002
EN 60747-5-2:2001 + A1:2002
DIN EN 60747-5-2 (VDE 0884 Teil 2):2003-01
(Option 050 only)
CSA
Approved under CSA Component Acceptance Notice
#5, File CA 88324
5
Insulation and Safety Related Specifications
Parameter
Symbol
Value
Units
Conditions
Min. External Clearance
(External Air Gap)
L(IO1)
9.6
mm
Measured from input terminals to output
terminals, shortest distance through air
Min. External Creepage
(External Tracking Path)
L(IO2)
10.0
mm
Measured from input terminals to output
terminals, shortest distance path along body
Min. Internal Clearance
(Internal Plastic Gap)
1.0
mm
Through insulation distance conductor to
conductor, usually the direct distance
between the photoemitter and photodetector
inside the optocoupler cavity
Min. Internal Creepage
(Internal Tracking Path)
4.0
mm
The shortest distance around the border
between two different insulating materials
measured between the emitter and detector
200
V
Comparative Tracking Index
CTI
Isolation Group
IIIa
DIN IEC 112/VDE 0303 PART 1
Material group (DIN VDE 0110)
Option 300 – surface mount classification is Class A in accordance with CECC 00802.
IEC/EN/DIN EN 60747-5-2 Insulation Characteristics (Option #050 Only)
Description
Symbol
Installation classification per DIN VDE 0110/1.89, Table 1
For rated mains voltage ≤600 V rms
For rated mains voltage ≤1000 V rms
Unit
I-IV
I-III
Climatic Classification (DIN IEC 68 part 1)
55/100/21
Pollution Degree (DIN VDE 0110 Part 1/1.89)
Maximum Working Insulation Voltage
Characteristic
2
VIORM
1414
V peak
Input to Output Test Voltage, Method b*
VPR = 1.875 x VIORM, 100% Production Test with
tm = 1 sec, Partial Discharge < 5 pC
VPR
2651
V peak
Input to Output Test Voltage, Method a*
VPR = 1.5 x VIORM, Type and sample test, tm = 60 sec,
Partial Discharge < 5 pC
VPR
2121
V peak
VIOTM
8000
V peak
TS
IS
PS,OUTPUT
150
400
700
°C
mA
mW
RS
>109
Ω
Highest Allowable Overvoltage*
(Transient Overvoltage, tini = 10 sec)
Safety-Limiting Values
(Maximum values allowed in the event of a failure,
also see Figure 11)
Case Temperature
Current (Input Current IF, PS = 0)
Output Power
Insulation Resistance at TS, VIO = 500 V
*Refer to the front of the Optocoupler section of the current catalog for a more detailed description of IEC/EN/DIN EN 60747-5-2 and other product safety regulations.
Note: Optocouplers providing safe electrical separation per IEC/EN/DIN EN 60747-5-2 do so only within the safety-limiting values to which they
are qualified. Protective cut-out switches must be used to ensure that the safety limits are not exceeded.
6
Absolute Maximum Ratings
Storage Temperature ..............................................................................................-55°C to +125°C
Operating Temperature (TA) ................................................................................. -55°C to +100°C
Junction Temperature (TJ) ......................................................................................................... 125°C
Reflow Temperature Profile ..............................................See Package Outline Drawings Section
Lead Solder Temperature ............................................................................................260°C for 10s
(up to seating plane)
Average Input Current - IF ........................................................................................................ 25 mA
Peak Input Current - IF ............................................................................................................... 40 mA
(50 ns maximum pulse width)
Reverse Input Voltage - VR ............................................................................................................2.5 V
(IR = 100 μA, Pin 1-2)
Input Power Dissipation.................................................................................... 60 mW @ TA = 85°C
(Derate at 2.2 mW/°C for operating temperatures above 85°C)
Reverse Output Photodiode Voltage ........................................................................................30 V
(Pin 6-5)
Reverse Input Photodiode Voltage ............................................................................................30 V
(Pin 3-4)
Recommended Operating Conditions
Storage Temperature .................................................................................................-40°C to +85°C
Operating Temperature ............................................................................................-40°C to +85°C
Average Input Current - IF .................................................................................................. 1 - 20 mA
Peak Input Current - IF ............................................................................................................... 35 mA
(50% duty cycle, 1 ms pulse width)
Reverse Output Photodiode Voltage ..................................................................................0 - 15 V
(Pin 6-5)
Reverse Input Photodiode Voltage ......................................................................................0 - 15 V
(Pin 3-4)
7
Electrical Specifications
TA = 25°C unless otherwise specified.
Parameter
Transfer Gain
Temperature
Coefficient of
Transfer Gain
DC NonLinearity
(Best Fit)
DC Nonlinearity
(Ends Fit)
Device
Min.
Typ.
Max.
K3
HCNR200
0.85
1.00
HCNR201
0.95
HCNR201
0.93
ΔK3 /ΔTA
NLBF
Test Conditions
Fig.
Note
1.15
5 nA < IPD < 50 μA,
0 V < VPD < 15 V
2,3
1
1.00
1.05
5 nA < IPD < 50 μA,
0 V < VPD < 15 V
1
1.00
1.07
-40°C < TA < 85°C,
5 nA < IPD < 50 μA,
0 V < VPD < 15 V
1
-65
%
5 nA < IPD < 50 μA,
0 V < VPD < 15 V
4,5,
6
0.01
0.05
5 nA < IPD < 50 μA,
0 V < VPD < 15 V
2
HCNR201
0.01
0.07
-40°C < TA < 85°C,
5 nA < IPD < 50 μA,
0 V < VPD < 15 V
2
5 nA < IPD < 50 μA,
0 V < VPD < 15 V
3
0.016
NLEF
%
HCNR200
0.25
0.50
0.75
HCNR201
0.36
0.48
0.72
-0.3
ILK
0.5
BVRPD
Photodiode
Capacitance
CPD
LED Forward
Voltage
VF
LED Junction
Capacitance
2,3
HCNR201
ΔK1/ΔTA
Temperature
Coefficient of
Forward Voltage
-40°C < TA < 85°C,
5 nA < IPD < 50 μA,
0 V < VPD < 15 V
0.25
Temperature
Coefficient
of K1
LED Reverse
Breakdown
Voltage
ppm/°C
0.01
K1
Photodiode
Reverse Breakdown Voltage
Units
HCNR200
Input Photodiode Current
Transfer Ratio
(IPD1/IF)
Photodiode
Leakage Current
8
Symbol
30
25
%
IF = 10 mA,
0 V < VPD1 < 15 V
7
%/°C
-40°C < TA < 85°C,
IF = 10 mA
0 V < VPD1 < 15 V
7
IF = 0 mA,
0 V < VPD < 15 V
8
nA
150
V
IR = 100 μA
22
pF
VPD = 0 V
V
IF = 10 mA
1.3
1.6
1.85
1.2
1.6
1.95
2.5
9
V
IF = 100 μA
ΔVF /ΔTA
-1.7
mV/°C
IF = 10 mA
CLED
80
pF
f = 1 MHz,
VF = 0 V
BVR
IF = 10 mA,
-40°C < TA < 85°C
9,
10
2
AC Electrical Specifications
TA = 25°C unless otherwise specified.
Units
Test
Conditions
9
MHz
IF = 10 mA
Application Circuit Bandwidth:
High Speed
High Precision
1.5
10
MHz
kHz
Application Circuit: IMRR
High Speed
95
dB
Parameter
Symbol
LED Bandwidth
f -3dB
Device
Min.
Typ.
Max.
freq = 60 Hz
Fig.
Note
16
17
6
6
16
6, 7
Package Characteristics
TA = 25°C unless otherwise specified.
Parameter
Symbol
Device
Min.
Input-Output
Momentary-Withstand
Voltage*
VISO
5000
Resistance
(Input-Output)
RI-O
1012
Typ.
Max.
Units
V rms
1013
Ω
1011
Capacitance
(Input-Output)
CI-O
0.4
0.6
pF
Test
Conditions
RH ≤50%,
t = 1 min.
Fig.
Note
4, 5
VO = 500 VDC
4
TA = 100°C,
VIO = 500 VDC
4
f = 1 MHz
4
*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 Application Note 1074, “Optocoupler Input-Output Endurance Voltage.”
Notes:
1. K3 is calculated from the slope of the best fit line of IPD2 vs. IPD1 with eleven equally distributed data points from 5 nA to 50 μA. This is approximately equal to IPD2/IPD1 at IF = 10 mA.
2. BEST FIT DC NONLINEARITY (NLBF) is the maximum deviation expressed as a percentage of the full scale output of a “best fit” straight line from
a graph of IPD2 vs. IPD1 with eleven equally distributed data points from 5 nA to 50 μA. IPD2 error to best fit line is the deviation below and above
the best fit line, expressed as a percentage of the full scale output.
3. ENDS FIT DC NONLINEARITY (NLEF) is the maximum deviation expressed as a percentage of full scale output of a straight line from the 5 nA to
the 50 μA data point on the graph of IPD2 vs. IPD1.
4. Device considered a two-terminal device: Pins 1, 2, 3, and 4 shorted together and pins 5, 6, 7, and 8 shorted together.
5. In accordance with UL 1577, each optocoupler is proof tested by applying an insulation test voltage of ≥6000 V rms for ≥1 second (leakage
detection current limit, II-O of 5 μA max.). This test is performed before the 100% production test for partial discharge (method b) shown in the
IEC/EN/DIN EN 60747-5-2 Insulation Characteris-tics Table (for Option #050 only).
6. Specific performance will depend on circuit topology and components.
7. IMRR is defined as the ratio of the signal gain (with signal applied to VIN of Figure 16) to the isolation mode gain (with VIN connected to input
common and the signal applied between the input and output commons) at 60 Hz, expressed in dB.
9
DELTA K3 – DRIFT OF K3 TRANSFER GAIN
1.04
1.02
1.00
0.98
0.96
NORMALIZED TO BEST-FIT K3 AT TA = 25°C,
0 V < VPD < 15 V
10.0
20.0
30.0
40.0
50.0
0 V < VPD < 15 V
0.01
0.005
0.0
-0.005
-0.01
= DELTA K3 MEAN
= DELTA K3 MEAN ± 2 • STD DEV
-0.015
-0.02
-55
60.0
-25
Figure 2. Normalized K3 vs. input IPD.
0.02
0.015
0.01
0 V < VPD < 15 V
5 nA < IPD < 50 µA
0.00
-55
-25
5
35
65
95
125
DELTA NLBF – DRIFT OF BEST-FIT NL – % PTS
NLBF – BEST-FIT NON-LINEARITY – %
0.025
0.005
0.01
0.005
0.0
-0.005
-0.01
-0.015
-0.02
-55
= DELTA NLBF MEAN
= DELTA NLBF MEAN ± 2 • STD DEV
-25
5
35
65
95
125
IF – FORWARD CURRENT – mA
6.0
4.0
2.0
65
-0.02
TA = 25 °C, 0 V < VPD < 15 V
-0.03
0.0
95
TA – TEMPERATURE – °C
Figure 8. Typical photodiode leakage vs.
temperature.
125
20.0
30.0
40.0
50.0
60.0
1.2
-55°C
1.1
-40°C
25°C
1.0
0.9
85°C
100°C
0.8
0.7
0.6
0.5
NORMALIZED TO K1 CTR
AT IF = 10 mA, TA = 25°C
0 V < VPD1 < 15 V
0.4
0.3
0.2
0.0
2.0
4.0
6.0
8.0 10.0 12.0 14.0 16.0
1.8
10
1
0.1
0.01
0.001
0.0001
1.20
10.0
Figure 7. Input photodiode CTR vs. LED input
current.
TA = 25°C
8.0
35
-0.01
IF – LED INPUT CURRENT – mA
100
5
0.00
Figure 4. IPD2 error vs. input IPD (see note 4).
0 V < VPD < 15 V
5 nA < IPD < 50 µA
VPD = 15 V
-25
0.01
IPD1 – INPUT PHOTODIODE CURRENT – µA
Figure 6. NLBF drift vs. temperature.
10.0
ILK – PHOTODIODE LEAKAGE – nA
125
= ERROR MEAN
= ERROR MEAN ± 2 • STD DEV
0.02
TA – TEMPERATURE – °C
Figure 5. NLBF vs. temperature.
10
95
0.02
0.015
TA – TEMPERATURE – °C
0.0
-55
65
Figure 3. K3 drift vs. temperature.
= NLBF 50TH PERCENTILE
= NLBF 90TH PERCENTILE
0.03
35
0.03
TA – TEMPERATURE – °C
IPD1 – INPUT PHOTODIODE CURRENT – µA
0.035
5
NORMALIZED K1 – INPUT PHOTODIODE CTR
0.94
0.0
0.015
VF – LED FORWARD VOLTAGE – V
NORMALIZED K3 – TRANSFER GAIN
= NORM K3 MEAN
= NORM K3 MEAN ± 2 • STD DEV
IPD2 ERROR FROM BEST-FIT LINE (% OF FS)
0.02
1.06
1.30
1.40
1.50
1.60
VF – FORWARD VOLTAGE – VOLTS
Figure 9. LED input current vs. forward voltage.
IF = 10 mA
1.7
1.6
1.5
1.4
1.3
1.2
-55
-25
5
35
65
95
125
TA – TEMPERATURE – °C
Figure 10. LED forward voltage vs. temperature.
1000
PS OUTPUT POWER – mV
IS INPUT CURRENT – mA
900
800
700
600
500
400
300
200
100
0
0
25
50
75
100
150
125
175
TS – CASE TEMPERATURE – °C
Figure 11. Thermal derating curve dependence of safety limiting value
with case temperature per IEC/EN/DIN EN 60747-5-2.
R2
R1
VIN
IPD1
PD1
+
A1
LED
IPD2
A2
+
PD2
VOUT
IF
A) BASIC TOPOLOGY
VCC
R2
C2
C1
R1
LED
VIN
-
-
R3
A1
+
PD1
PD2
PD2
A2
+
VOUT
B) PRACTICAL CIRCUIT
Figure 12. Basic isolation amplifier.
VCC
VIN
-
-
+
+
VOUT
A) POSITIVE INPUT
B) POSITIVE OUTPUT
VIN
-
-
+
+
VOUT
C) NEGATIVE INPUT
Figure 13. Unipolar circuit topologies.
11
D) NEGATIVE OUTPUT
VCC1
VCC2
VCC1
IOS1
IOS2
VIN
-
-
+
+
VOUT
A) SINGLE OPTOCOUPLER
VCC
+
VIN
VOUT
+
+
B) DUAL OPTOCOUPLER
Figure 14. Bipolar circuit topologies.
R2
+IIN
R1
D1
-
VOUT
PD2
PD1
+
+
LED
R3
-IIN
A) RECEIVER
VCC
R1
LED
VIN
+IOUT
R2
PD1
+
D1
Q1
PD2
+
R3
-IOUT
B) TRANSMITTER
Figure 15. Loop-powered 4-20 mA current loop circuits.
12
VCC2 +5 V
VCC1 +5 V
LED
R3
10 K
R5
10 K
R2
68 K
R7
470
VOUT
Q2
2N3904
R1
68 K
Q4
2N3904
Q1
2N3906
VIN
Q3
2N3906
R4
10
PD1
R6
10
PD2
Figure 16. High-speed low-cost analog isolator.
VCC1 +15 V
VCC2 +15 V
C3
0.1µ
C5
0.1µ
R4
2.2 K
R5
270
Q1
2N3906
INPUT
BNC
R6
6.8 K
C1
47 P
R1
200 K
1%
C2
33 P
7
C4
0.1µ
6
LT1097
- 2
A2 3
+
4
PD2
C6
0.1µ
R3
33 K
VEE1 -15 V
50 K
1%
7
2 6
3 A1
LT1097
+
4
PD1
R2
174 K
D1
1N4150
LED
VEE2 -15 V
Figure 17. Precision analog isolation amplifier.
C3
C1
R6
180 K
R2
180 K
OC1
PD1
VIN
R1
50 K
BALANCE
R3
180 K
VCC1 = +15 V
VEE1 = -15 V
Figure 18. Bipolar isolation amplifier.
13
D1
+
R4
680
OC1
LED
OC2
LED
+
D2
C2
10 pf
R5
680
R7
50 K
GAIN
OC1
PD2
VMAG
+
OC2
PD1
10 pf
10 pf
OC2
PD2
OUTPUT
BNC
C3
C1
R5
180 K
D1
GAIN
+
R4
680
R1
220 K
R6
50 K
D3
-
VIN
10 pf
10 pf
OC1
PD1
R2
10 K
R3
4.7 K
VMAG
+
OC1
LED
+
D2
OC1
PD2
D4
-
VCC
+
C2
10 pf
+
-
R7
6.8 K
R8
2.2 K
VSIGN
VCC1 = +15 V
VEE1 = -15 V
Figure 19. Magnitude/sign isolation amplifier.
Figure 20. SPICE model listing.
14
OC2
6N139
0.001 µF
+ILOOP
HCNR200
LED
R1
10 kΩ
R5
80 kΩ
Z1
5.1 V
R4
100 Ω
HCNR200
PD1
+
VCC
5.5 V
0.1 µF
LM158
-
2N3906
-
+
R2
10 kΩ
VOUT
LM158
HCNR200
PD2
0.001 µF
-ILOOP
R3
25 Ω
2
Design Equations:
VOUT / ILOOP = K3 (R5 R3) / R1 + R3)
K3 = K2 / K1 = Constant = 1
Note:
The two OP-AMPS shown are two separate LM158, and not two channels in a single dual package,
otherwise the loop side and output side will not be properly isolated.
Figure 21. 4 to 20 mA HCNR200 receiver circuit.
+I LOOP
12V~40V
4 ~ 20mA
4mA (Vin=0.8V)
20mA(Vin=4V)
R8
100kΩ
Q3
2N3904
Vcc
5.5V
R2
150 Ω
Q2
IC3
+
LM158
C3
100nF
C1
1nF
Q4
Vin
0.8V~4V
“0” @ 2200Hz
“1” @ 1200Hz
PD1/IC1
IC2
LM158
+
Q1
R4
10k Ω
1nF
C2
PD2/IC1
R3
Design Equations:
(ILOOP/Vin)=K3(R5+R3)/(R5R1)
K3 = K2/K1 = Constant ≈ 1
Note:
The two OP-AMPS shown are two separate LM158 IC’s, and NOT dual channels in a
single package, otherwise, the LOOP side and input side will not be properly isolated;
The 5V1 Zener should be properly selected to ensure that it conducts at 187μA;
15
R6
150 Ω
2N3906
10k Ω
Figure 22. 4 to 20 mA HCNR200 transmitter circuit.
R7
3k2Ω
2N3904
LED/IC1
HCNR200
R1
80k Ω
2N3904
5V1
R5
25 Ω
- I LOOP
Theory of Operation
Figure 1 illustrates how the HCNR200/201 high-linearity
optocoupler is configured. The basic optocoupler consists of an LED and two photodiodes. The LED and one of
the photodiodes (PD1) is on the input leadframe and the
other photodiode (PD2) is on the output leadframe. The
package of the optocoupler is constructed so that each
photodiode receives approximately the same amount of
light from the LED.
Notice that IPD1 depends ONLY on the input voltage and
the value of R1 and is independent of the light output
characteristics of the LED. As the light output of the
LED changes with temperature, amplifier A1 adjusts IF
to compensate and maintain a constant current in PD1.
Also notice that IPD1 is exactly proportional to VIN, giving
a very linear relationship between the input voltage and
the photodiode current.
An external feedback amplifier can be used with PD1 to
monitor the light output of the LED and automatically
adjust the LED current to compensate for any non-linearities or changes in light output of the LED. The feedback
amplifier acts to stabilize and linearize the light output
of the LED. The output photodiode then converts the
stable, linear light output of the LED into a current, which
can then be converted back into a voltage by another
amplifier.
The relationship between the input optical power and
the output current of a photodiode is very linear. Therefore, by stabilizing and linearizing IPD1, the light output of
the LED is also stabilized and linearized. And since light
from the LED falls on both of the photodiodes, IPD2 will be
stabilized as well.
Figure 12a illustrates the basic circuit topology for
implementing a simple isolation amplifier using the
HCNR200/201 optocoupler. Besides the optocoupler,
two external op-amps and two resistors are required.
This simple circuit is actually a bit too simple to function
properly in an actual circuit, but it is quite useful for explaining how the basic isolation amplifier circuit works (a
few more components and a circuit change are required
to make a practical circuit, like the one shown in Figure
12b).
The operation of the basic circuit may not be immediately obvious just from inspecting Figure 12a, particularly the input part of the circuit. Stated briefly, amplifier
A1 adjusts the LED current (IF), and therefore the current
in PD1 (IPD1), to maintain its “+” input terminal at 0 V. For
example, increasing the input voltage would tend to increase the voltage of the “+” input terminal of A1 above
0 V. A1 amplifies that increase, causing IF to increase, as
well as IPD1. Because of the way that PD1 is connected,
IPD1 will pull the “+” terminal of the op-amp back toward
ground. A1 will continue to increase IF until its “+” terminal is back at 0 V. Assuming that A1 is a perfect op-amp,
no current flows into the inputs of A1; therefore, all of the
current flowing through R1 will flow through PD1. Since
the “+” input of A1 is at 0 V, the current through R1, and
therefore IPD1 as well, is equal to VIN/R1.
Essentially, amplifier A1 adjusts IF so that
IPD1 = VIN/R1.
16
The physical construction of the package determines the
relative amounts of light that fall on the two photodiodes
and, therefore, the ratio of the photodiode currents. This
results in very stable operation over time and temperature. The photodiode current ratio can be expressed as a
constant, K, where
K = IPD2/IPD1.
Amplifier A2 and resistor R2 form a trans-resistance amplifier that converts IPD2 back into a voltage, VOUT, where
VOUT = IPD2*R2.
Combining the above three equations yields an overall
expression relating the output voltage to the input voltage,
VOUT /VIN = K*(R2/R1).
Therefore the relationship between VIN and VOUT is constant, linear, and independent of the light output
characteristics of the LED. The gain of the basic isolation
amplifier circuit can be adjusted simply by adjusting the
ratio of R2 to R1. The parameter K (called K3 in the electrical specifications) can be thought of as the gain of the
optocoupler and is specified in the data sheet.
Remember, the circuit in Figure 12a is simplified in order
to explain the basic circuit operation. A practical circuit,
more like Figure 12b, will require a few additional components to stabilize the input part of the circuit, to limit the
LED current, or to optimize circuit performance. Example
application circuits will be discussed later in the data
sheet.
Circuit Design Flexibility
Circuit design with the HCNR200/201 is very flexible
because the LED and both photodiodes are accessible
to the designer. This allows the designer to make performance trade-offs that would otherwise be difficult to
make with commercially available isolation amplifiers
(e.g., bandwidth vs. accuracy vs. cost). Analog isolation
circuits can be designed for applications that have either
unipolar (e.g., 0-10 V) or bipolar (e.g., ±10 V) signals, with
positive or negative input or output voltages. Several
simplified circuit topologies illustrating the design flexibility of the HCNR200/201 are discussed below.
to worry about. However, the second circuit requires two
optocouplers, separate gain adjustments for the positive and negative portions of the signal, and can exhibit
crossover distortion near zero volts. The correct circuit to
choose for an application would depend on the requirements of that particular application. As with the basic
isolation amplifier circuit in Figure 12a, the circuits in Figure 14 are simplified and would require a few additional
components to function properly. Two example circuits
that operate with bipolar input signals are discussed in
the next section.
The circuit in Figure 12a is configured to be non-inverting with positive input and output voltages. By simply
changing the polarity of one or both of the photodiodes,
the LED, or the op-amp inputs, it is possible to implement
other circuit configurations as well. Figure 13 illustrates
how to change the basic circuit to accommodate both
positive and negative input and output voltages. The input and output circuits can be matched to achieve any
combination of positive and negative voltages, allowing
for both inverting and non-inverting circuits.
As a final example of circuit design flexibility, the simplified schematics in Figure 15 illustrate how to implement
4-20 mA analog current-loop transmitter and receiver
circuits using the HCNR200/201 optocoupler. An important feature of these circuits is that the loop side of the
circuit is powered entirely by the loop current, eliminating the need for an isolated power supply.
All of the configurations described above are unipolar
(single polarity); the circuits cannot accommodate a signal that might swing both positive and negative. It is possible, however, to use the HCNR200/201 optocoupler to
implement a bipolar isolation amplifier. Two topologies
that allow for bipolar operation are shown in Figure 14.
The circuit in Figure 14a uses two current sources to
offset the signal so that it appears to be unipolar to the
optocoupler. Current source IOS1 provides enough offset
to ensure that IPD1 is always positive. The second current
source, IOS2, provides an offset of opposite polarity to obtain a net circuit offset of zero. Current sources IOS1 and
IOS2 can be implemented simply as resistors connected to
suitable voltage sources.
The circuit in Figure 14b uses two optocouplers to obtain
bipolar operation. The first optocoupler handles the positive voltage excursions, while the second optocoupler
handles the negative ones. The output photodiodes are
connected in an antiparallel configuration so that they
produce output signals of opposite polarity.
The first circuit has the obvious advantage of requiring
only one optocoupler; however, the offset performance
of the circuit is dependent on the matching of IOS1 and
IOS2 and is also dependent on the gain of the optocoupler.
Changes in the gain of the optocoupler will directly affect the offset of the circuit.
The offset performance of the second circuit, on the
other hand, is much more stable; it is independent of
optocoupler gain and has no matched current sources
17
The input and output circuits in Figure 15a are the same
as the negative input and positive output circuits shown
in Figures 13c and 13b, except for the addition of R3 and
zener diode D1 on the input side of the circuit. D1 regulates the supply voltage for the input amplifier, while R3
forms a current divider with R1 to scale the loop current
down from 20 mA to an appropriate level for the input
circuit (<50 μA).
As in the simpler circuits, the input amplifier adjusts the
LED current so that both of its input terminals are at the
same voltage. The loop current is then divided
between R1 and R3. IPD1 is equal to the current in R1 and
is given by the following equation:
IPD1 = ILOOP*R3/(R1+R3).
Combining the above equation with the equations used
for Figure 12a yields an overall expression relating the
output voltage to the loop current,
VOUT/ILOOP = K*(R2*R3)/(R1+R3).
Again, you can see that the relationship is constant, linear, and independent of the characteristics of the LED.
The 4-20 mA transmitter circuit in Figure 15b is a little different from the previous circuits, particularly the output
circuit. The output circuit does not directly generate an
output voltage which is sensed by R2, it instead uses Q1
to generate an output current which flows through R3.
This output current generates a voltage across R3, which
is then sensed by R2. An analysis similar to the one above
yields the following expression relating output current
to input voltage:
ILOOP /VIN = K*(R2+R3)/(R1*R3).
The preceding circuits were presented to illustrate the
flexibility in designing analog isolation circuits using the
HCNR200/201. The next section presents several complete schematics to illustrate practical applications of the
HCNR200/201.
Example Application Circuits
The circuit shown in Figure 16 is a high-speed low-cost
circuit designed for use in the feedback path of switchmode power supplies. This application requires good
bandwidth, low cost and stable gain, but does not require very high accuracy. This circuit is a good example
of how a designer can trade off accuracy to achieve
improvements in bandwidth and cost. The circuit has a
bandwidth of about 1.5 MHz with stable gain characteristics and requires few external components.
Although it may not appear so at first glance, the circuit
in Figure 16 is essentially the same as the circuit in Figure 12a. Amplifier A1 is comprised of Q1, Q2, R3 and R4,
while amplifier A2 is comprised of Q3, Q4, R5, R6 and R7.
The circuit operates in the same manner as well; the only
difference is the performance of amplifiers A1 and A2.
The lower gains, higher input currents and higher offset
voltages affect the accuracy of the circuit, but not the
way it operates. Because the basic circuit operation has
not changed, the circuit still has good gain stability. The
use of discrete transistors instead of op-amps allowed
the design to trade off accuracy to achieve good bandwidth and gain stability at low cost.
To get into a little more detail about the circuit, R1 is selected to achieve an LED current of about 7-10 mA at the
nominal input operating voltage according to the following equation:
IF = (VIN/R1)/K1,
where K1 (i.e., IPD1/IF) of the optocoupler is typically about
0.5%. R2 is then selected to achieve the desired output
voltage according to the equation,
VOUT/VIN = R2/R1.
The purpose of R4 and R6 is to improve the dynamic response (i.e., stability) of the input and output circuits by
lowering the local loop gains. R3 and R5 are selected to
provide enough current to drive the bases of Q2 and Q4.
And R7 is selected so that Q4 operates at about the same
collector current as Q2.
The next circuit, shown in Figure 17, is designed to achieve
the highest possible accuracy at a reasonable cost. The
high accuracy and wide dynamic range of the circuit is
achieved by using low-cost precision op-amps with very
low input bias currents and offset voltages and is limited
by the performance of the optocoupler. The circuit is designed to operate with input and output voltages from
1 mV to 10 V.
18
The circuit operates in the same way as the others. The
only major differences are the two compensation capacitors and additional LED drive circuitry. In the high-speed
circuit discussed above, the input and output circuits are
stabilized by reducing the local loop gains of the input
and output circuits. Because reducing the loop gains
would decrease the accuracy of the circuit, two compensation capacitors, C1 and C2, are instead used to improve
circuit stability. These capacitors also limit the bandwidth
of the circuit to about 10 kHz and can be used to reduce
the output noise of the circuit by reducing its bandwidth
even further.
The additional LED drive circuitry (Q1 and R3 through
R6) helps to maintain the accuracy and bandwidth of the
circuit over the entire range of input voltages. Without
these components, the transconductance of the LED
driver would decrease at low input voltages and LED
currents. This would reduce the loop gain of the input
circuit, reducing circuit accuracy and bandwidth. D1 prevents excessive reverse voltage from being applied to
the LED when the LED turns off completely.
No offset adjustment of the circuit is necessary; the gain
can be adjusted to unity by simply adjusting the 50 kohm
potentiometer that is part of R2. Any OP-97 type of opamp can be used in the circuit, such as the LT1097 from
Linear Technology or the AD705 from Analog Devices,
both of which offer pA bias currents, μV offset voltages
and are low cost. The input terminals of the op-amps and
the photodiodes are connected in the circuit using Kelvin
connections to help ensure the accuracy of the circuit.
The next two circuits illustrate how the HCNR200/201 can
be used with bipolar input signals. The isolation amplifier
in Figure 18 is a practical implementation of the circuit
shown in Figure 14b. It uses two optocouplers, OC1 and
OC2; OC1 handles the positive portions of the input signal and OC2 handles the negative portions.
Diodes D1 and D2 help reduce crossover distortion by
keeping both amplifiers active during both positive and
negative portions of the input signal. For example, when
the input signal positive, optocoupler OC1 is active while
OC2 is turned off. However, the amplifier controlling OC2
is kept active by D2, allowing it to turn on OC2 more rapidly when the input signal goes negative, thereby reducing crossover distortion.
Balance control R1 adjusts the relative gain for the positive and negative portions of the input signal, gain control R7 adjusts the overall gain of the isolation amplifier,
and capacitors C1-C3 provide compensation to stabilize
the amplifiers.
The final circuit shown in Figure 19 isolates a bipolar
analog signal using only one optocoupler and generates
two output signals: an analog signal proportional to the
magnitude of the input signal and a digital signal corresponding to the sign of the input signal. This circuit is
especially useful for applications where the output of
the circuit is going to be applied to an analog-to-digital
converter. The primary advantages of this circuit are very
good linearity and offset, with only a single gain adjustment and no offset or balance adjustments.
HCNR200/201 SPICE Model
Figure 20 is the net list of a SPICE macro-model for the
HCNR200/201 high-linearity optocoupler. The macromodel accurately reflects the primary characteristics of
the HCNR200/201 and should facilitate the design and
understanding of circuits using the HCNR200/201 optocoupler.
To achieve very high linearity for bipolar signals, the
gain should be exactly the same for both positive and
negative input polarities. This circuit achieves excellent
linearity by using a single optocoupler and a single input
resistor, which guarantees identical gain for both positive and negative polarities of the input signal. This precise matching of gain for both polarities is much more
difficult to obtain when separate components are used
for the different input polarities, such as is the previous
circuit.
The circuit in Figure 19 is actually very similar to the previous circuit. As mentioned above, only one optocoupler
is used. Because a photodiode can conduct current in
only one direction, two diodes (D1 and D2) are used to
steer the input current to the appropriate terminal of
input photodiode PD1 to allow bipolar input currents.
Normally the forward voltage drops of the diodes would
cause a serious linearity or accuracy problem. However,
an additional amplifier is used to provide an appropriate
offset voltage to the other amplifiers that exactly cancels
the diode voltage drops to maintain circuit accuracy.
Diodes D3 and D4 perform two different functions; the
diodes keep their respective amplifiers active independent of the input signal polarity (as in the previous circuit), and they also provide the feedback signal to PD1
that cancels the voltage drops of diodes D1 and D2.
Either a comparator or an extra op-amp can be used to
sense the polarity of the input signal and drive an inexpensive digital optocoupler, like a 6N139.
It is also possible to convert this circuit into a fully bipolar
circuit (with a bipolar output signal) by using the output
of the 6N139 to drive some CMOS switches to switch the
polarity of PD2 depending on the polarity of the input
signal, obtaining a bipolar output voltage swing.
For product information and a complete list of distributors, please go to our website:
www.avagotech.com
Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies in the United States and other countries.
Data subject to change. Copyright © 2005-2011 Avago Technologies. All rights reserved. Obsoletes AV01-0567EN
AV02-0886EN - December 10, 2011
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