1
XTR112, XTR114
RTD
XTR112
XTR114
4-20 mA
V
PS
V
O
R
L
R
G
V
LIN
V
REG
+
7.5V to 36V
I
R
I
R
XTR112: I
R
= 250
A
XTR114: I
R
= 100
A
XTR112
XTR114
4-20mA CURRENT TRANSMITTERS
with Sensor Excitation and Linearization
FEATURES
q
LOW UNADJUSTED ERROR
q
PRECISION CURRENT SOURCES
XTR112: Two 250
A
XTR114: Two 100
A
q
RTD OR BRIDGE EXCITATION
q
LINEARIZATION
q
TWO OR THREE-WIRE RTD OPERATION
q
LOW OFFSET DRIFT: 0.4
V/
C
q
LOW OUTPUT CURRENT NOISE: 30nAp-p
q
HIGH PSR: 110dB min
q
HIGH CMR: 86dB min
q
WIDE SUPPLY RANGE: 7.5V TO 36V
q
SO-14 SOIC PACKAGE
APPLICATIONS
q
INDUSTRIAL PROCESS CONTROL
q
FACTORY AUTOMATION
q
SCADA REMOTE DATA ACQUISITION
q
REMOTE TEMPERATURE AND PRESSURE
TRANSDUCERS
DESCRIPTION
The XTR112 and XTR114 are monolithic 4-20mA,
two-wire current transmitters. They provide complete
current excitation for high impedance platinum RTD
temperature sensors and bridges, instrumentation am-
plifier, and current output circuitry on a single inte-
grated circuit. The XTR112 has two 250
A current
sources while the XTR114 has two 100
A sources for
RTD excitation.
Versatile linearization circuitry provides a 2nd-order
correction to the RTD, typically achieving a 40:1
improvement in linearity.
Instrumentation amplifier gain can be configured for a
wide range of temperature or pressure measurements.
Total unadjusted error of the complete current trans-
mitter is low enough to permit use without adjustment
in many applications. This includes zero output cur-
rent drift, span drift and nonlinearity. The XTR112
and XTR114 operate on loop power supply voltages
down to 7.5V.
Both are available in an SO-14 surface-mount pack-
age and are specified for the 40
C to +85
C indus-
trial temperature range.
1998 Burr-Brown Corporation
PDS-1473A
Printed in U.S.A. December, 1998
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/ Cable: BBRCORP Telex: 066-6491 FAX: (520) 889-1510 Immediate Product Info: (800) 548-6132
200
C
Pt1000 NONLINEARITY CORRECTION
USING XTR112 and XTR114
Process Temperature (
C)
+850
C
5
4
3
2
1
0
1
Uncorrected
RTD Nonlinearity
Corrected
Nonlinearity
Nonlinearity (%)
XTR112
XTR114
SBOS101
2
XTR112, XTR114
SPECIFICATIONS
At T
A
= +25
C, V+
= 24V, and TIP29C external transistor, unless otherwise noted.
XTR112U
XTR112UA
XTR114U
XTR114UA
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
OUTPUT
Output Current Equation
A
Output Current, Specified Range
4
20
T
T
mA
Over-Scale Limit
24
27
30
T
T
T
mA
Under-Scale Limit: XTR112
I
REG
= 0
0.9
1.3
1.7
T
T
T
mA
XTR114
0.6
1
1.4
T
T
T
mA
ZERO OUTPUT
(1)
V
IN
= 0V, R
G
=
4
T
mA
Initial Error
5
25
T
50
A
vs Temperature
0.07
0.5
T
0.9
A/
C
vs Supply Voltage, V+
V+ = 7.5V to 36V
0.04
0.2
T
T
A/V
vs Common-Mode Voltage
V
CM
= 1.25V to 3.5V
(2)
0.02
T
A/V
vs V
REG
Output Current
0.3
T
A/mA
Noise: 0.1Hz to 10Hz
0.03
T
Ap-p
SPAN
Span Equation (transconductance)
S = 40/R
G
T
A/V
Initial Error
(3)
Full Scale (V
IN
) = 50mV
0.05
0.2
T
0.4
%
vs Temperature
(3)
3
25
T
T
ppm/
C
Nonlinearity: Ideal Input
(4)
Full Scale (V
IN
) = 50mV
0.003
0.01
T
T
%
INPUT
(5)
Offset Voltage
V
CM
= 2V
50
100
T
250
V
vs Temperature
0.4
1.5
T
3
V/
C
vs Supply Voltage, V+
V+ = 7.5V to 36V
0.3
3
T
T
V/V
vs Common-Mode Voltage,
V
CM
= 1.25V to 3.5V
(2)
10
50
T
100
V/V
RTI (CMRR)
Common-Mode Input Range
(2)
1.25
3.5
T
T
V
Input Bias Current
5
25
T
50
nA
vs Temperature
20
T
pA/
C
Input Offset Current
0.2
3
T
10
nA
vs Temperature
5
T
pA/
C
Impedance: Differential
0.1 || 1
T
G
|| pF
Common-Mode
5 || 10
T
G
|| pF
Noise: 0.1Hz to 10Hz
0.6
T
Vp-p
CURRENT SOURCES
V
O
= 2V
(6)
Current: XTR112
250
T
A
XTR114
100
T
A
Accuracy
0.05
0.2
T
0.4
%
vs Temperature
15
35
T
75
ppm/
C
vs Power Supply, V+
V+ = 7.5V to 36V
10
25
T
T
ppm/V
Matching
0.02
0.1
T
0.2
%
vs Temperature
3
15
T
30
ppm/
C
vs Power Supply, V+
V+ = 7.5V to 36V
1
10
T
T
ppm/V
Compliance Voltage, Positive
(V+) 3
(V+) 2.5
T
T
V
Negative
(2)
0
0.2
T
T
V
Output Impedance: XTR112
500
T
M
XTR114
1.2
T
G
Noise: 0.1Hz to 10Hz: XTR112
0.001
T
Ap-p
XTR114
0.0004
T
Ap-p
V
REG
(2)
5.1
T
V
Accuracy
0.02
0.1
T
T
V
vs Temperature
0.2
T
mV/
C
vs Supply Voltage, V+
1
T
mV/V
Output Current: XTR112
1, +2.1
T
mA
XTR114
1, +2.4
T
mA
Output Impedance
75
T
LINEARIZATION
R
LIN
(internal)
1
T
k
Accuracy
0.2
0.5
T
1
%
vs Temperature
25
100
T
T
ppm/
C
POWER SUPPLY
Specified Voltage
+24
T
V
Operating Voltage Range
+7.5
+36
T
T
V
TEMPERATURE RANGE
Specification, T
MIN
to T
MAX
40
+85
T
T
C
Operating /Storage Range
55
+125
T
T
C
Thermal Resistance,
JA
SO-14 Surface-Mount
100
T
C/W
I
O
= V
IN
(40/R
G
) + 4mA, V
IN
in Volts, R
G
in
T
Specification same as XTR112U, XTR114U.
NOTES: (1) Describes accuracy of the 4mA low-scale offset current. Does not include input amplifier effects. Can be trimmed to zero. (2) Voltage measured with
respect to I
RET
pin. (3) Does not include initial error or TCR of gain-setting resistor, R
G
. (4) Increasing the full-scale input range improves nonlinearity. (5) Does not
include Zero Output initial error. (6) Current source output voltage with respect to I
RET
pin.
3
XTR112, XTR114
Power Supply, V+ (referenced to I
O
pin) .......................................... 40V
Input Voltage, V
IN
, V
IN
(referenced to I
O
pin) ............................ 0V to V+
Storage Temperature Range ....................................... 55
C to +125
C
Lead Temperature (soldering, 10s) .............................................. +300
C
Output Current Limit ............................................................... Continuous
Junction Temperature ................................................................... +165
C
NOTE: (1) Stresses above these ratings may cause permanent damage.
Exposure to absolute maximum conditions for extended periods may degrade
device reliability.
ABSOLUTE MAXIMUM RATINGS
(1)
Top View
SO-14
PIN CONFIGURATION
+
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.
PACKAGE
SPECIFIED
CURRENT
DRAWING
TEMPERATURE
ORDERING
TRANSPORT
PRODUCT
SOURCES
PACKAGE
NUMBER
(1)
RANGE
NUMBER
(2)
MEDIA
XTR112U
2 x 250
A
SO-14 Surface Mount
235
40
C to +85
C
XTR112U
Rails
"
"
"
"
"
XTR112U/2K5
Tape and Reel
XTR112UA
2 x 250
A
SO-14 Surface Mount
235
40
C to +85
C
XTR112UA
Rails
"
"
"
"
"
XTR112UA/2K5
Tape and Reel
XTR114U
2 x 100
A
SO-14 Surface Mount
235
40
C to +85
C
XTR114U
Rails
"
"
"
"
"
XTR114U/2K5
Tape and Reel
XTR114UA
2 x 100
A
SO-14 Surface Mount
235
40
C to +85
C
XTR114UA
Rails
"
"
"
"
"
XTR114UA/2K5
Tape and Reel
NOTES: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. (2) Models with a slash (/) are
available only in Tape and Reel in the quantities indicated (e.g., /2K5 indicates 2500 devices per reel). Ordering 2500 pieces of "XTR112UA/2K5" will get a single
2500-piece Tape and Reel. For detailed Tape and Reel mechanical information, refer to Appendix B of Burr-Brown IC Data Book.
PACKAGE/ORDERING INFORMATION
I
R1
V
IN
R
G
R
G
NC
I
RET
I
O
I
R2
V
IN
V
LIN
V
REG
V+
B (Base)
E (Emitter)
NC = No Connection
XTR112 and XTR114
1
2
3
4
5
6
7
14
13
12
11
10
9
8
+
4
XTR112, XTR114
FUNCTIONAL BLOCK DIAGRAM
975
6
I = 100
A +
100
A
I
R1
I
R2
25
V+
Q
1
9
B
10
11
4
13
2
3
8
E
V
IN
R
G
I
O
= 4mA + V
IN
40
R
G
( )
5.1V
R
G
R
LIN
1k
V
IN
+
V
IN
I
RET
7
V
REG
XTR112: I
R1
= I
R2
= 250
A
XTR114: I
R1
= I
R2
= 100
A
14
1
12
I
R2
I
R1
V
LIN
5
XTR112, XTR114
TYPICAL PERFORMANCE CURVES
At T
A
= +25
C, and V+ = 24V, unless otherwise noted.
20mA
STEP RESPONSE
25
s/div
4
m
A/div
R
G
= 125
R
G
= 2k
4mA
10
100
1k
10k
100k
Frequency (Hz)
1M
110
100
90
80
70
60
50
40
30
20
Common-Mode Rejection Ratio (dB)
COMMON-MODE REJECTION RATIO vs FREQUENCY
R
G
= 2k
R
G
= 125
100
1k
10k
100k
Frequency (Hz)
TRANSCONDUCTANCE vs FREQUENCY
1M
50
40
30
20
10
0
Transconductance (20 Log mA/V)
R
G
= 125
R
G
= 500
R
G
= 2k
75
50
25
0
25
50
75
100
Temperature (
C)
OVER-SCALE CURRENT vs TEMPERATURE
125
29
28
27
26
25
24
23
Over-Scale Current (mA)
V+ = 7.5V
V+ = 36V
V+ = 24V
With External Transistor
75
50
25
0
25
50
75
100
Temperature (
C)
UNDER-SCALE CURRENT vs TEMPERATURE
125
1.45
1.4
1.35
1.3
1.25
1.2
1.15
1.1
1.05
1
0.95
Under-Scale Current (mA)
XTR114
XTR112
10
100
1k
10k
100k
Frequency (Hz)
POWER-SUPPLY REJECTION RATIO vs FREQUENCY
1M
140
120
100
80
60
40
20
0
Power Supply Rejection Ratio (dB)
R
G
= 2k
R
G
= 125
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