XTR112.PDF

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®
XTR
XTR
114
112
XTR112
XTR114
4-20mA CURRENT TRANSMITTERS
with Sensor Excitation and Linearization
FEATURES
q
LOW UNADJUSTED ERROR
q
PRECISION CURRENT SOURCES
XTR112: Two 250
µ
A
XTR114: Two 100
µ
A
q
RTD OR BRIDGE EXCITATION
q
LINEARIZATION
q
TWO OR THREE-WIRE RTD OPERATION
q
q
q
q
q
q
LOW OFFSET DRIFT: 0.4
µ
V/
°
C
LOW OUTPUT CURRENT NOISE: 30nAp-p
HIGH PSR: 110dB min
HIGH CMR: 86dB min
WIDE SUPPLY RANGE: 7.5V TO 36V
SO-14 SOIC PACKAGE
Pt1000 NONLINEARITY CORRECTION
USING XTR112 and XTR114
5
4
Nonlinearity (%)
3
2
1
0
–1
–200°C
Process Temperature (°C)
+850°C
APPLICATIONS
q
INDUSTRIAL PROCESS CONTROL
q
FACTORY AUTOMATION
q
SCADA REMOTE DATA ACQUISITION
q
REMOTE TEMPERATURE AND PRESSURE
TRANSDUCERS
Uncorrected
RTD Nonlinearity
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 250µA current
sources while the XTR114 has two 100µA 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.
Corrected
Nonlinearity
I
R
I
R
V
LIN
V
REG
+
7.5V to 36V
V
PS
4-20 mA
R
G
RTD
–
XTR112:
I
R
= 250µA
XTR114:
I
R
= 100µA
XTR112
XTR114
V
O
R
L
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
®
©
1998 Burr-Brown Corporation
PDS-1473A
1
Printed in U.S.A. December, 1998
XTR112, XTR114
SPECIFICATIONS
At T
A
= +25°C, V+ = 24V, and TIP29C external transistor, unless otherwise noted.
XTR112U
XTR114U
PARAMETER
OUTPUT
Output Current Equation
Output Current, Specified Range
Over-Scale Limit
Under-Scale Limit: XTR112
XTR114
ZERO OUTPUT
(1)
Initial Error
vs Temperature
vs Supply Voltage, V+
vs Common-Mode Voltage
vs V
REG
Output Current
Noise: 0.1Hz to 10Hz
SPAN
Span Equation (transconductance)
Initial Error
(3)
vs Temperature
(3)
Nonlinearity: Ideal Input
(4)
INPUT
(5)
Offset Voltage
vs Temperature
vs Supply Voltage, V+
vs Common-Mode Voltage,
RTI (CMRR)
Common-Mode Input Range
(2)
Input Bias Current
vs Temperature
Input Offset Current
vs Temperature
Impedance: Differential
Common-Mode
Noise: 0.1Hz to 10Hz
CURRENT SOURCES
Current: XTR112
XTR114
Accuracy
vs Temperature
vs Power Supply, V+
Matching
vs Temperature
vs Power Supply, V+
Compliance Voltage, Positive
Negative
(2)
Output Impedance: XTR112
XTR114
Noise: 0.1Hz to 10Hz: XTR112
XTR114
V
REG(2)
Accuracy
vs Temperature
vs Supply Voltage, V+
Output Current: XTR112
XTR114
Output Impedance
LINEARIZATION
R
LIN
(internal)
Accuracy
vs Temperature
POWER SUPPLY
Specified Voltage
Operating Voltage Range
TEMPERATURE RANGE
Specification, T
MIN
to T
MAX
Operating /Storage Range
Thermal Resistance,
θ
JA
SO-14 Surface-Mount
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.
®
XTR112UA
XTR114UA
MAX
MIN
TYP
MAX
UNITS
A
mA
mA
mA
mA
mA
µA
µA/°C
µA/V
µA/V
µA/mA
µAp-p
A/V
%
ppm/°C
%
µV
µV/°C
µV/V
µV/V
V
nA
pA/°C
nA
pA/°C
GΩ || pF
GΩ || pF
µVp-p
µA
µA
%
ppm/°C
ppm/V
%
ppm/°C
ppm/V
V
V
MΩ
GΩ
µAp-p
µAp-p
V
V
mV/°C
mV/V
mA
mA
Ω
kΩ
%
ppm/°C
V
V
°C
°C
°C/W
CONDITIONS
MIN
TYP
I
REG
= 0
V
IN
= 0V, R
G
=
∞
4
24
0.9
0.6
I
O
= V
IN
• (40/R
G
) + 4mA, V
IN
in Volts, R
G
in
Ω
20
T
27
30
T
T
1.3
1.7
T
T
1
1.4
T
T
4
±5
±0.07
0.04
0.02
0.3
0.03
S = 40/R
G
±0.05
±3
0.003
±50
±0.4
±0.3
±10
±25
±0.5
0.2
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
+36
+85
+125
100
T
T
T
T
T
T
T
T
±50
±0.9
T
V+ = 7.5V to 36V
V
CM
= 1.25V to 3.5V
(2)
Full Scale (V
IN
) = 50mV
Full Scale (V
IN
) = 50mV
V
CM
= 2V
V+ = 7.5V to 36V
V
CM
= 1.25V to 3.5V
(2)
1.25
±0.2
±25
0.01
±100
±1.5
±3
±50
3.5
25
±3
±0.4
T
T
±250
±3
T
±100
T
50
±10
5
20
±0.2
5
0.1 || 1
5 || 10
0.6
V
O
= 2V
(6)
250
100
±0.05
±15
±10
±0.02
±3
1
(V+) –2.5
–0.2
500
1.2
0.001
0.0004
5.1
±0.02
±0.2
1
–1, +2.1
–1, +2.4
75
1
±0.2
±25
+24
+7.5
–40
–55
V+ = 7.5V to 36V
V+ = 7.5V to 36V
(V+) –3
0
±0.2
±35
±25
±0.1
±15
10
T
T
±0.4
±75
T
±0.2
±30
T
±0.1
T
±0.5
±100
±1
T
T
T
T
XTR112, XTR114
2
PIN CONFIGURATION
Top View
XTR112 and XTR114
I
R1
V
IN
R
G
R
G
NC
I
RET
I
O
–
ABSOLUTE MAXIMUM RATINGS
(1)
SO-14
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.
1
2
3
4
5
6
7
14 I
R2
13 V
IN
12 V
LIN
11 V
REG
10 V+
9
8
B (Base)
E (Emitter)
+
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.
NC = No Connection
PACKAGE/ORDERING INFORMATION
CURRENT
SOURCES
2 x 250µA
"
2 x 250µA
"
2 x 100µA
"
2 x 100µA
"
PACKAGE
DRAWING
NUMBER
(1)
235
"
235
"
235
"
235
"
SPECIFIED
TEMPERATURE
RANGE
–40°C to +85°C
"
–40°C to +85°C
"
–40°C to +85°C
"
–40°C to +85°C
"
ORDERING
NUMBER
(2)
XTR112U
XTR112U/2K5
XTR112UA
XTR112UA/2K5
XTR114U
XTR114U/2K5
XTR114UA
XTR114UA/2K5
TRANSPORT
MEDIA
Rails
Tape and Reel
Rails
Tape and Reel
Rails
Tape and Reel
Rails
Tape and Reel
PRODUCT
XTR112U
"
XTR112UA
"
XTR114U
"
XTR114UA
"
PACKAGE
SO-14 Surface Mount
"
SO-14 Surface Mount
"
SO-14 Surface Mount
"
SO-14 Surface Mount
"
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.
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.
®
3
XTR112, XTR114
FUNCTIONAL BLOCK DIAGRAM
V
LIN
I
R1
12
1
I
R2
14
I
R1
I
R2
V
REG
V+
11
10
+
V
IN
XTR112:
I
R1
= I
R2
= 250µA
XTR114:
I
R1
= I
R2
= 100µA
13
4
R
LIN
1kΩ
R
G
3
2
I = 100µA +
V
IN
R
G
5.1V
B
100µA
9
Q
1
E
8
–
V
IN
975Ω
25Ω
7
40
(
R
)
G
I
O
= 4mA + V
IN
•
6
I
RET
®
XTR112, XTR114
4
TYPICAL PERFORMANCE CURVES
At T
A
= +25°C, and V+ = 24V, unless otherwise noted.
TRANSCONDUCTANCE vs FREQUENCY
50
Transconductance (20 Log mA/V)
R
G
= 500Ω
40
R
G
= 125Ω
20mA
4mA/div
STEP RESPONSE
R
G
= 2kΩ
30
R
G
= 125Ω
20
R
G
= 2kΩ
4mA
10
0
100
1k
10k
Frequency (Hz)
100k
1M
25µs/div
COMMON-MODE REJECTION RATIO vs FREQUENCY
110
100
140
POWER-SUPPLY REJECTION RATIO vs FREQUENCY
Power Supply Rejection Ratio (dB)
Common-Mode Rejection Ratio (dB)
120
100
80
60
40
20
0
10
100
1k
10k
100k
1M
R
G
= 2kΩ
R
G
= 125Ω
90
80
70
60
50
40
30
20
10
100
1k
10k
100k
1M
Frequency (Hz)
R
G
= 2kΩ
R
G
= 125Ω
Frequency (Hz)
OVER-SCALE CURRENT vs TEMPERATURE
29
With External Transistor
28
27
V+ = 36V
26
V+ = 7.5V
25
V+ = 24V
24
23
–75
–50
–25
0
25
50
75
100
125
Temperature (°C)
1.45
1.4
UNDER-SCALE CURRENT vs TEMPERATURE
Under-Scale Current (mA)
Over-Scale Current (mA)
1.35
1.3
1.25
1.2
1.15
1.1
1.05
1
0.95
–75
–50
XTR112
XTR114
–25
0
25
50
75
100
125
Temperature (°C)
®
5
XTR112, XTR114

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