TEXAS INSTRUMENTS XTR112, XTR1144 Technical data

®

XTR114

XTR112

XTR112

4-20mA CURRENT TRANSMITTERS

with Sensor Excitation and Linearization

FEATURES

● LOW UNADJUSTED ERROR

● PRECISION CURRENT SOURCES

XTR112: Two 250µA
XTR114: Two 100µA

● RTD OR BRIDGE EXCITATION

● LINEARIZATION

● TWO OR THREE-WIRE RTD OPERATION

● LOW OFFSET DRIFT: 0.4µV/°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

XTR114

APPLICATIONS

● INDUSTRIAL PROCESS CONTROL

● FACTORY AUTOMATION

● SCADA REMOTE DATA ACQUISITION

● REMOTE TEMPERATURE AND PRESSURE

TRANSDUCERS

Pt1000 NONLINEARITY CORRECTION

5

4

3

2

USING XTR112 and XTR114

Uncorrected

RTD Nonlinearity

SBOS101

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 am­plifier, and current output circuitry on a single inte-

1

Nonlinearity (%)

0

–1

–200°C

Process Temperature (°C)

Corrected

Nonlinearity

+850°C

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.

I

R

I

R

V

LIN

V

+

REG

7.5V to 36V

Instrumentation amplifier gain can be configured for a

= 100µA

R

4-20 mA

wide range of temperature or pressure measurements.
Total unadjusted error of the complete current trans­mitter is low enough to permit use without adjustment
in many applications. This includes zero output cur­rent 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-

RTD

R

G

XTR112
XTR114

–

XTR112: IR = 250µA
XTR114: I

age and are specified for the –40°C to +85°C indus­trial temperature range.

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: [phone]

Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: [phone] • Immediate Product Info: [phone]

©

1998 Burr-Brown Corporation PDS-1473A Printed in U.S.A. December, 1998

1

XTR112, XTR114

V

PS

V

O

R

L

®

SPECIFICATIONS

At TA = +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 ✻✻mA

Over-Scale Limit 24 27 30 ✻✻✻ mA
Under-Scale Limit: XTR112 I

XTR114 0.6 1 1.4 ✻✻✻ mA

ZERO OUTPUT

(1)

= 0 0.9 1.3 1.7 ✻✻✻ mA

REG

VIN = 0V, RG = ∞ 4 ✻ mA

Initial Error ±5 ±25 ✻ ±50 µA

vs Temperature ±0.07 ±0.5 ✻ ±0.9 µA/°C
vs Supply Voltage, V+ V+ = 7.5V to 36V 0.04 0.2 ✻✻ µA/V
vs Common-Mode Voltage
vs V

Output Current 0.3 ✻ µA/mA

REG

Noise: 0.1Hz to 10Hz 0.03 ✻ µAp-p

VCM = 1.25V to 3.5V

(2)

SPAN

Span Equation (transconductance)
Initial Error

Nonlinearity: Ideal Input

INPUT

(3)

vs Temperature

(5)

(3)

(4)

Full Scale (VIN) = 50mV ±0.05 ±0.2 ✻ ±0.4 %

Full Scale (VIN) = 50mV 0.003 0.01 ✻✻ %

Offset Voltage VCM = 2V ±50 ±100 ✻ ±250 µV

vs Temperature ±0.4 ±1.5 ✻ ±3 µV/°C
vs Supply Voltage, V+ V+ = 7.5V to 36V ±0.3 ±3 ✻✻ µV/V
vs Common-Mode Voltage, V

RTI (CMRR)

Common-Mode Input Range

(2)

= 1.25V to 3.5V

CM

(2)

Input Bias Current 525 ✻ 50 nA

vs Temperature 20 ✻ pA/°C

Input Offset Current ±0.2 ±3 ✻ ±10 nA

vs Temperature 5 ✻ pA/°C

Impedance: Differential 0.1 || 1 ✻ GΩ || pF

Common-Mode 5 || 10 ✻ GΩ || pF

Noise: 0.1Hz to 10Hz 0.6 ✻ µVp-p
CURRENT SOURCES V

Current: XTR112 250 ✻ µA

= 2V

O

(6)

XTR114 100 ✻ µA

Accuracy ±0.05 ±0.2 ✻ ±0.4 %

vs Temperature ±15 ±35 ✻ ±75 ppm/°C
vs Power Supply, V+ V+ = 7.5V to 36V ±10 ±25 ✻✻ ppm/V

Matching ±0.02 ±0.1 ✻ ±0.2 %

vs Temperature ±3 ±15 ✻ ±30 ppm/°C
vs Power Supply, V+ V+ = 7.5V to 36V 1 10 ✻✻ ppm/V

Compliance Voltage, Positive (V+) –3

Negative

(2)

Output Impedance: XTR112 500 ✻ MΩ

XTR114 1.2 ✻ GΩ

Noise: 0.1Hz to 10Hz: XTR112 0.001 ✻ µAp-p

XTR114 0.0004 ✻ µAp-p

(2)

V

REG

Accuracy ±0.02 ±0.1 ✻✻ V

vs Temperature ±0.2 ✻ mV/°C
vs Supply Voltage, V+ 1 ✻ mV/V

Output Current: XTR112 –1, +2.1 ✻ mA

XTR114 –1, +2.4 ✻ mA

Output Impedance 75 ✻ Ω

LINEARIZATION

R

(internal) 1 ✻ kΩ

LIN

Accuracy ±0.2 ±0.5 ✻ ±1%
vs Temperature ±25 ±100 ✻✻ ppm/°C

POWER SUPPLY

Specified Voltage +24 ✻ V
Operating Voltage Range +7.5 +36 ✻✻V

TEMPERATURE RANGE

Specification, T
Operating /Storage Range –55 +125 ✻✻°C
Thermal Resistance,

SO-14 Surface-Mount 100 ✻ °C/W

MIN

to T

MAX

θ

JA

✻ 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
include Zero Output initial error. (6) Current source output voltage with respect to I

pin. (3) Does not include initial error or TCR of gain-setting resistor, RG. (4) Increasing the full-scale input range improves nonlinearity. (5) Does not

RET

®

XTR112, XTR114

IO = VIN • (40/RG) + 4mA, VIN in Volts, RG in Ω

0.02 ✻ µA/V

S = 40/R

G

✻ A/V

±3 ±25 ✻✻ ppm/°C

±10 ±50 ✻ ±100 µV/V

1.25 3.5 ✻✻V

(V+) –2.5

✻✻ V

0 –0.2 ✻✻ V

5.1 ✻ V

–40 +85 ✻✻°C

pin.

RET

2

PIN CONFIGURATION

Top View SO-14

XTR112 and XTR114

1

I

R1
–+

2

VIN

3

R

G

4

R

G

5

NC

6

I

RET

7

I

O

NC = No Connection

14
13
12
11
10

9
8

I

R2

V

IN

V

LIN

V

REG

V+
B (Base)
E (Emitter)

ABSOLUTE MAXIMUM RATINGS

Power Supply, V+ (referenced to IO pin).......................................... 40V

Input Voltage, 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.

+

–

, VIN (referenced to IO pin) ............................ 0V to V+

IN

(1)

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.

PACKAGE/ORDERING INFORMATION

PRODUCT SOURCES PACKAGE NUMBER

CURRENT DRAWING TEMPERATURE ORDERING TRANSPORT

XTR112U 2 x 250µA SO-14 Surface Mount 235 –40°C to +85°C XTR112U Rails

" " " " " XTR112U/2K5 Tape and Reel

XTR112UA 2 x 250µA SO-14 Surface Mount 235 –40°C to +85°C XTR112UA Rails

" " " " " XTR112UA/2K5 Tape and Reel

XTR114U 2 x 100µA SO-14 Surface Mount 235 –40°C to +85°C XTR114U Rails

" " " " " XTR114U/2K5 Tape and Reel

XTR114UA 2 x 100µA 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 SPECIFIED

(1)

RANGE NUMBER

(2)

MEDIA

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

13

+

V

IN

I

R2

1

14

I

R1

I

R2

V

REG

11

5.1V

V+

10

XTR112: I
XTR114: I

= I

= 250µA

R1

R2

= I

= 100µA

R1

R2

4

R

LIN

1kΩ

R

G

100µA

3

V

2

–

V

IN

I = 100µA +

IN

R

G

975Ω

25Ω

B

Q

9

1

E
8

7

IO = 4mA + V

IN

40

•

( )

R

G

6

I

RET

®

XTR112, XTR114

4

TYPICAL PERFORMANCE CURVES

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)

RG = 2kΩ

RG = 125Ω

At TA = +25°C, and V+ = 24V, unless otherwise noted.

50

40

30

20

10

Transconductance (20 Log mA/V)

0

100 1k 10k 100k

110
100

90
80
70
60
50
40
30

Common-Mode Rejection Ratio (dB)

20

10 100 1k 10k 100k

TRANSCONDUCTANCE vs FREQUENCY

RG = 500Ω

RG = 2kΩ

Frequency (Hz)

COMMON-MODE REJECTION RATIO vs FREQUENCY

R

G

RG = 2kΩ

Frequency (Hz)

RG = 125Ω

= 125Ω

1M

1M

STEP RESPONSE

RG = 2kΩ

20mA

RG = 125Ω

4mA/div

4mA

25µs/div

29

28

27

26

25

Over-Scale Current (mA)

24

23

OVER-SCALE CURRENT vs TEMPERATURE

V+ = 36V

–75 –50 –25 0 25 50 75 100

With External Transistor

V+ = 7.5V

V+ = 24V

Temperature (°C)

125

1.45

1.4

1.35

1.3

1.25

1.2

1.15

1.1

Under-Scale Current (mA)

1.05
1

0.95

5

UNDER-SCALE CURRENT vs TEMPERATURE

XTR112

XTR114

–75 –50 –25 0 25 50 75 100

Temperature (°C)

XTR112, XTR114

125

®

TYPICAL PERFORMANCE CURVES (CONT)

At TA = +25°C, and V+ = 24V, unless otherwise noted.

INPUT VOLTAGE AND CURRENT

10k

1k

100

Input Voltage Noise (nV/√Hz)

10

1 10 100 1k 10k

25

20

15

10

5

Input Bias and Offset Current (nA)

0

–75 –50 –25 0 25 50 75 100

NOISE DENSITY vs FREQUENCY

Current Noise

Voltage Noise

Frequency (Hz)

INPUT BIAS AND OFFSET CURRENT

vs TEMPERATURE

Temperature (°C)

ZERO OUTPUT AND REFERENCE

10k

1k

100

Input Current Noise (fA/√Hz)

10

100k

+I

B

–I

B

I

OS

125

10k

1k

100

Noise (pA/√Hz)

XTR114

10

1 10 100 1k 10k

4
2

0
–2
–4
–6
–8

Zero Output Current Error (µA)

–10
–12

–75 –50 –25 0 25 50 75 100

CURRENT NOISE vs FREQUENCY

Zero Output Current

XTR112

Reference Current

100k

Frequency (Hz)

ZERO OUTPUT CURRENT ERROR

vs TEMPERATURE

125

Temperature (°C)

80
70
60
50
40
30

Percent of Units (%)

20
10

0

0

0.2

0.4

®

XTR112, XTR114

INPUT OFFSET VOLTAGE DRIFT

PRODUCTION DISTRIBUTION

Typical production distribution

of packaged units. XTR112 and

XTR114 included.

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Input Offset Voltage Drift (µV/°C)

2.2

2.4

2.6

2.8

3.0

ZERO OUTPUT DRIFT

40
35
30
25
20
15

Percent of Units (%)

10

5

0

0

0.025

PRODUCTION DISTRIBUTION

Typical production distribution

0.05

0.075

0.1

0.2

0.15

0.125

0.175

0.225

Zero Output Drift (µA/°C)

of packaged units. XTR112

and XTR114 included.

0.25

0.3

0.275

0.35

0.325

0.4

0.375

0.425

0.45

0.5

0.475

6