1988 Burr-Brown Corporation
PDS-881G
Printed in U.S.A. December, 1995
FPO
ISO212P
APPLICATIONS
q
INDUSTRIAL PROCESS CONTROL:
Transducer Channel Isolator for
Thermocouples, RTDs, Pressure
Bridges, Flow Meters
q
4mA TO 20mA LOOP ISOLATION
q
MOTOR AND SCR CONTROL
q
GROUND LOOP ELIMINATION
q
ANALYTICAL MEASUREMENTS
q
POWER PLANT MONITORING
q
DATA ACQUISITION/TEST EQUIPMENT
ISOLATION
q
MULTIPLEXED SYSTEMS WITH CHANNEL
TO CHANNEL ISOLATION
Offset
Adjust
8
7
I/P
3
+I/P
1
f
4
6
Com 1
2
5
38
37
O/P Low
Isolation Barrier
B
+V Out
SS 1
Com 2
+V
CC
31
32
Clock Out
34
Clock In
35
DC/DC
Converter
O/P High
Offset
Adjust
V Out
SS 1
Low Cost, Two-Port Isolated, 1500Vrms
ISOLATION AMPLIFIER
FEATURES
q
12-BIT ACCURACY
q
2.5mA (typ) QUIESCENT CURRENT
q
LOW PROFILE (LESS THAN 0.5" HIGH)
q
SMALL FOOTPRINT
q
EXTERNAL POWER CAPABILITY
(
8V at 5mA)
q
"MASTER/SLAVES" SYNCHRONIZATION
CAPABILITY
q
INPUT OFFSET ADJUSTMENT
q
LOW POWER (53mW)
q
SINGLE 10V TO 15V SUPPLY OPERATION
DESCRIPTION
The ISO212P signal isolation amplifier is a member of
a series of low-cost isolation products from Burr-
Brown. The low-profile SIL plastic package allows
PCB spacings of 0.5" to be achieved, and the small
footprint results in efficient use of board space.
To provide isolation, the design uses high-efficiency,
miniature toroidal transformers in both the signal and
power paths. An uncommitted input amplifier and an
isolated external bipolar supply ensure the majority of
input interfacing or conditioning needs can be met. The
ISO212P accepts an input voltage range of
5V for
single 15V supply operation or
3.0V for single 10V
supply operation.
International Airport Industrial Park Mailing Address: PO Box 11400, Tucson, AZ 85734 Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 Tel: (520) 746-1111 Twx: 910-952-1111
Internet: http://www.burr-brown.com/ FAXLine: (800) 548-6133 (US/Canada Only) Cable: BBRCORP Telex: 066-6491 FAX: (520) 889-1510 Immediate Product Info: (800) 548-6132
ISO212P
2
SPECIFICATIONS
ELECTRICAL
At T
A
= +25
C and V
CC
= +15V, unless otherwise noted.
ISO212JP
ISO212KP, JP-15
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
ISOLATION
Voltage
Rated Continuous
AC, 50Hz
750
1500
Vrms
DC
1060
2120
VDC
100% Test (AC, 50Hz)
Partial Discharge
1s : <5pC
1200
2400
Vrms
Isolation-Mode Rejection
(1)
V
ISO
= Rated
Continuous 60Hz
AC
115
T
(9)
dB
DC
160
T
dB
Barrier Resistance
10
10
T
Barrier Capacitance
12
T
pF
Leakage Current
(8)
V
ISO
= 240Vrms, 60Hz
1
2
T
T
Arms
V
ISO
= 240Vrms, 50Hz
1.6
T
Arms
GAIN
Initial Error
1
2
T
T
% FSR
(2)
Gain vs Temperature
20
50
T
T
ppm of FSR/
C
Nonlinearity
(3)
:
KP
V
O
= 5V to +5V
0.04
0.05
0.015
0.025
%FSR
JP-15
0.04
0.05
%FSR
INPUT OFFSET VOLTAGE
Offset Voltage RTI: KP
10
10/G
7.5
7.5/G
mV
JP-15
10
10/G
mV
vs Temperature
30
30/G
T
V/
C
vs Power Supply
(4)
V
CC
= 14V to 16V
1.5
T
mV/V
Adjustment Range
20
T
mV
INPUT CURRENT
Bias
50
T
nA
Offset
4
T
nA
INPUT
Voltage Range
(5)
G = 1
5
T
V
Resistance
10
12
T
OUTPUT
Output Impedance
3
T
k
Voltage Range
Out Hi to Out Lo
5
T
V
Min Load = 1M
Ripple Voltage
(6)
f = 0 to 100kHz
8
T
mVp-p
f = 0 to 5kHz
0.4
T
mVrms
Ouput Compliance
Out Hi or Out Lo
7.5
V
FREQUENCY RESPONSE
Small Signal Bandwidth
I/P = 1Vp-p, 3dB
1
T
kHz
G = 1
Full Signal Bandwidth
I/P = 10Vp-p,
200
T
Hz
G = 1
G = 10 (3dB)
1.8
kHz
ISOLATED POWER OUTPUTS
Voltage Outputs (
V
SS 1
)
(7)
No Load
7.5
8
T
T
VDC
vs Temperature
8
T
mV/
C
vs Load
90
T
mV/mA
Current Output
(7)
(Both Loaded)
5
T
mA
(One Loaded)
8
T
mA
POWER SUPPLIES
Rated Voltage
Rated Performance
15
T
V
Voltage Range
(5)
11.4 to 16
T
T
V
Quiescent Current
No Load
2.5
3.5
T
T
mA
TEMPERATURE RANGE
Specification
0
+70
T
T
C
Operating
25
+85
T
T
C
NOTES: (1) Isolation-mode rejection is the ratio of the change in output voltage to a change in isolation barrier voltage. It is a function of frequency. (2) FSR = Full
Scale Range = 10V. (3) Nonlinearity is the peak deviation of the output voltage from the best-fit straight line. It is expressed as the ratio of deviation to FSR. (4) Power
Supply Rejection is the change in V
OS
/Supply Change. (5) At V
CC
= +10.0V, input voltage range =
3.0V min. (6) Ripple is the residual component of the barrier carrier
frequency generated internally. (7) Derated at V
CC
< +15V. (8) Tested at 2400Vrms, 50Hz limit 16
A. (9) Asterisk (
T
) same as ISO212JP.
ISO212P
3
PIN CONFIGURATION
Bottom View
31 +V
CC
35 Clock In
37 O/P Low
Com 2 32
Clock Out 34
O/P High 38
Com 1 2
f
B
4
+V
SS1
6
Offset Adjust 8
1 +I/P
3 I/P
5 V
SS 1
7 Offset Adjust
ABSOLUTE MAXIMUM RATINGS
Supply Voltage Without Damage ......................................................... 18V
Continuous Isolation Voltage Across Barrier: JP ......................... 750Vrms
KP, JP-15 ........... 1500Vrms
Storage Temperature Range ............................................ 25
C to 100
C
Lead Temperature (soldering, 10s) ................................................ +300
C
Amplifier Output Short-Circuit Duration ................ Continuous to Common
Output Voltage Hi or Lo to Com 2 ..................................................
V
CC
/2
PACKAGE
DRAWING
TEMPERATURE
PRODUCT
PACKAGE
NUMBER
(1)
RANGE
ISO212JP
38-Pin Plastic SIP
326
25
C to +85
C
ISO212JP-15
38-Pin Plastic SIP
326
25
C to +85
C
ISO212KP
38-Pin Plastic SIP
326
25
C to +85
C
NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix C of Burr-Brown IC Data Book.
PACKAGE/ORDERING INFORMATION
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degradation
to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric
changes could cause the device not to meet its published
specifications.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user's own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
SINE RESPONSE (f = 200Hz)
0
+5
Time (ms)
Output Voltage (V)
0
5
5
10
V
IN
= 5V, G = 1
VOLTAGE OUT vs SUPPLY VOLTAGE +V
CC
17
7
6
5
4
3
2
1
0
Supply Voltage V
CC
(V)
Voltage Out (V)
16 15
14 13
12
11 10
9
8
7
6
5
4
+V
OUT
V
OUT
(Absolute)
V
IN
V
OUT
V
OUT
+V
OUT
V
OUT
Ideal
Ideal
V
IN
TYPICAL PERFORMANCE CURVES
At T
A
= +25
C, V
S
=
15V, unless otherwise noted.
ISO212P
4
TYPICAL PERFORMANCE CURVES
(CONT)
At T
A
= +25
C and V
S
=
15V, unless otherwise noted.
SINE RESPONSE (f = 2kHz)
Output Voltage (mV)
+500
0
500
0
500
1000
Time (s)
V = 0.5V, G = 1
IN
STEP RESPONSE (f = 200Hz)
Output Voltage (V)
+5
0
5
0
5
10
Time (ms)
V = 5V, G = 1
IN
STEP RESPONSE (f = 2kHz)
0
500
1000
Time (s)
Output Voltage (mV)
+500
0
500
V = 0.5V, G = 1
IN
IMR vs FREQUENCY
1k
10k
100k
1M
10M
85
80
75
70
65
60
55
50
45
40
Frequency (Hz)
IMR (dB)
100M
LINEARITY vs CLOCK-IN RATE
30
40
50
60
70
80
90
100
Clock-In Rate (kHz)
100
90
80
70
60
50
40
30
20
10
0
Linearity Error (m%)
0
0.5
1
1.5
2
2.5
30
40
50
60
70
80
90
100
GAIN ERROR vs CLOCK-IN RATE
Clock-In Rate (kHz)
Gain Error (% FSR)
ISO212P
5
DISCUSSION
OF SPECIFICATIONS
The ISO212P is intended for applications where isolation
and input signal conditioning are required. Best signal-to-
noise performance is obtained when the input amplifier gain
setting is such that V
OUT
has a full scale range of
5V. The
bandwidth is typically 1kHz, making the device ideal for use
in conjunction with sensors that monitor slowly varying
processes. To power external functions or networks, 5mA at
8V typical is available at the isolated port.
LINEARITY PERFORMANCE
The ISO212P offers linearity performance compatible with
12-bit resolution systems (0.025%). Note that the specifica-
tion is based on a best-fit straight line.
OPTIONAL OFFSET VOLTAGE ADJUSTMENT
In many applications, the untrimmed input offset voltage
will be adequate. For situations where it is necessary to trim
the offset, a potentiometer can be used. See Figure 1 for
details. It is important to keep the traces to the offset adjust
pins as short as practical, because noise can be injected into
the input op amp via this route.
INPUT PROTECTION
If the ISO212P is used in systems where a transducer or
sensor does not derive its power from the isolated power
available from the device, then some input protection must
be present to prevent damage to the input op amp when the
ISO212P is not powered. A resistor of 5k
should be
included to limit the output impedance of the signal source.
Where the op amp is configured for an inverting gain, then
R
IN
of the gain setting network can be used. For non-
FIGURE 1. Power Supply and Signal Connections Shown for Non-Inverting, Unity Gain Configuration.
0.1F
100k
Offset
Adjust
8
7
5
6
V
Out
SS 1
+V
Out
SS 1
1
2
+I/P
Com 1
5k
V
IN
V
OUT
38
37
32
O/P High
O/P Low
Com 2
34
35
Clock
Out
Clock
In
31
+V
CC
(1)
+
+
(2)
(2)
I/P
f
B
3
4
Input Ground Plane
Output Ground Plane
Isolation
Barrier
10F
10F
10F Tantalum
100H
+
inverting configurations, a separate resistor is required.
Neglecting this point may also lead to problems when
powering on the ISO212P.
USING
V
SS1
TO POWER EXTERNAL CIRCUITRY
The DC/DC converter in the ISO212P runs at a switching
frequency of 25kHz. Internal rectification and filtering is
sufficient for most applications at low frequencies or with no
external networks connected.
The ripple on
V
SS1
will typically be 100mVp-p at 25kHz.
Loading the supplies will increase the ripple unless extra
filtering is added externally; a capacitor of 1
F is normally
sufficient for most applications, although in some cases
10
F may be required. Noise introduced onto
V
SS1
should
be decoupled to prevent degraded performance.
THEORY OF OPERATION
The ISO212P has no galvanic connection between the input
and output. The analog input signal referenced to the input
common (Com 1) is multiplied by the gain of the input
amplifier and accurately reproduced at the output. The
output section uses a differential design so either the HI or
LO pin may be referenced to the output common (Com 2).
This allows simple input signal inversion while maintaining
the high impedance input configuration. A simplified dia-
gram of the ISO212P is shown in Figure 2. The design
consists of a DC/DC converter, an uncommitted input opera-
tional amplifier, a modulator circuit and a demodulator
circuit. Magnetic isolation is provided by separate trans-
formers in the power and signal paths.
The DC/DC converter provides power and synchronization
signals across the isolation barrier to operate the operational
amplifier and modulator circuitry. It also has sufficient
capacity to power external input signal conditioning net-
NOTES: (1) Optional voltage offset adjust compo-
nents. (2) 10
F decoupling to be used with external
loads connected.
PDF 
ZIP