TEXAS INSTRUMENTS XTR105 Technical data

–200°C

Pt100 NONLINEARITY CORRECTION

USING XTR105

Process Temperature (°C)

+850°C

5

4

3

2

1

0

–1

Uncorrected

RTD Nonlinearity

Corrected

Nonlinearity

Nonlinearity (%)

XTR105

XTR105

XTR105

SBOS061B – FEBRUARY 1997 – REVISED AUGUST 2004

4-20mA CURRENT TRANSMITTER

with Sensor Excitation and Linearization

FEATURES

● LOW UNADJUSTED ERROR

● TWO PRECISION CURRENT SOURCES: 800µA each

● LINEARIZATION

● 2- OR 3-WIRE RTD OPERATION

● LOW OFFSET DRIFT: 0.4µV/°C

● LOW OUTPUT CURRENT NOISE: 30nA

PP

APPLICATIONS

● INDUSTRIAL PROCESS CONTROL

● FACTORY AUTOMATION

● SCADA REMOTE DATA ACQUISITION

● REMOTE TEMPERATURE AND PRESSURE

TRANSDUCERS

● HIGH PSR: 110dB minimum

● HIGH CMR: 86dB minimum

● WIDE SUPPLY RANGE: 7.5V to 36V

● DIP-14 AND SO-14 PACKAGES

DESCRIPTION

The XTR105 is a monolithic 4-20mA, 2-wire current transmit­ter with two precision current sources. It provides complete
current excitation for platinum RTD temperature sensors and
bridges, instrumentation amplifiers, and current output cir­cuitry on a single integrated circuit.

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 transmitter is low
enough to permit use without adjustment in many applica­tions. This includes zero output current drift, span drift, and
nonlinearity. The XTR105 operates on loop power-supply
voltages down to 7.5V.

RTD

The XTR105 is available in DIP-14 and SO-14 surface­mount packages and is specified for the –40°C to +85°C
industrial temperature range.

= 0.8mA

I

R

IR = 0.8mA

R

G

+

–

V

LIN

XTR105

V

REG

7.5V to 36V

4-20 mA

V

PS

V

O

R

L

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.

Copyright © 1997-2004, Texas Instruments Incorporated

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ABSOLUTE MAXIMUM RATINGS

(1)

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

, V

Input Voltage, V

(referenced to the IO pin) ....................0V to V+

IN+

IN–

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 those listed under “Absolute Maximum Ratings”
may cause permanent damage to the device. Exposure to absolute maximum
conditions for extended periods may affect device reliability.

ELECTROSTATIC
DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Texas Instru­ments 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

(1)

SPECIFIED

PACKAGE TEMPERATURE PACKAGE ORDERING TRANSPORT

PRODUCT PACKAGE-LEAD DESIGNATOR RANGE MARKING NUMBER MEDIA, QUANTITY

XTR105 DIP-14 N –40°C to +85°C XTR105PA XTR105PA Rails, 25

" """XTR105P XTR105P Rails, 25

XTR105 SO-14 Surface-Mount D –40°C to +85°C XTR105UA XTR105UA Rails, 58

" """XTR105UA XTR105UA/2K5 Tape and Reel, 2500

XTR105 SO-14 Surface-Mount D –40°C to +85°C XTR105U XTR105U Rails, 58

" """XTR105U XTR105U/2K5 Tape and Reel, 2500

NOTE: (1) For the most current package and ordering information, see the Package Option Addendum located at the end of this data sheet.

FUNCTIONAL BLOCK DIAGRAM

V

LIN

I

R1

12

13

+

V

IN

4

R

LIN

R

G

3

2

–

V

IN

1kΩ

6

I

RET

I

R2

1

14

800µA 800µA

100µA

V

I = 100µA +

R

IN
G

975Ω

V

REG

11

5.1V

25Ω

7

IO = 4mA + V

V+

10

B

Q

1

9

E
8

40

•

( )

IN

R

G

PIN CONFIGURATION

Top View DIP and SO

1

I

R1
– +

2

VIN

3

R

G

4

R

G

5

NC

6

I

RET

7

I

O

NC = No Internal Connection

14
13
12
11
10

9
8

I

R2

V

IN

V

LIN

V

REG

V+
B (Base)
E (Emitter)

2

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XTR105

SBOS061B

ELECTRICAL CHARACTERISTICS

At TA = +25°C, V+ = 24V, and TIP29C external transistor, unless otherwise noted.

XTR105P, U XTR105PA, UA
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 I

ZERO OUTPUT

(1)

= 0V 1.8 2.2 2.6 ✻✻✻ 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 ✻ µA

VCM = 1.25V to 3.5V

(2)

SPAN

Span Equation (transconductance)
Initial Error

vs Temperature

Nonlinearity, Ideal Input

INPUT

(3)

(3)

(4)

(5)

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, VCM = 1.25V to 3.5V

RTI (CMRR)

Common-Mode Input Range

(2)

(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 ✻ µV
CURRENT SOURCES VO = 2V

(6)

Current 800 ✻ 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 150 ✻ MΩ
Noise, 0.1Hz to 10Hz 0.003 ✻ µA

(2)

V

REG

Accuracy ±0.02 ±0.1 ✻✻ V

vs Temperature ±0.2 ✻ mV/°C

vs Supply Voltage, V+ 1 ✻ mV/V
Output Current ±1 ✻ 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 +24 ✻ V
Voltage Range +7.5 +36 ✻✻V

TEMPERATURE RANGE

Specification, T
Operating –55 +125 ✻✻°C

MIN

to T

MAX

Storage –55 +125 ✻✻°C
Thermal Resistance,

DIP-14 80 ✻ °C/W

θ

JA

SO-14 Surface-Mount 100 ✻ °C/W

✻ Specification same as XTR105P and XTR105U.
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
(3) Does not include initial error or TCR of gain-setting resistor, R

RET

pin.

(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.

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

.

G

PP

PP

PP

XTR105

SBOS061B

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3

TYPICAL CHARACTERISTICS

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

Common-Mode Rejection (dB)

30
20

TRANSCONDUCTANCE vs FREQUENCY

RG = 500Ω

RG = 2kΩ

Frequency (Hz)

COMMON-MODE REJECTION vs FREQUENCY

Full-Scale Input = 50mV

RG = 2kΩ

10 100 1k 10k 100k

Frequency (Hz)

R

G

= 125Ω

RG = 125Ω

1M

1M

STEP RESPONSE

RG = 2kΩ

20mA

RG = 125Ω

4mA/div

4mA

25µs/div

140

120

100

80

60

40

Power Supply Rejection (dB)

20

POWER-SUPPLY REJECTION vs FREQUENCY

RG = 2kΩ

0

10 100 1k 10k 100k

Frequency (Hz)

RG = 125Ω

1M

29

28

27

V+ = 36V

26

25

Over-Scale Current (mA)

24

23

–75 –50 –25 0 25 50 75 100

4

OVER-SCALE CURRENT vs TEMPERATURE

With External Transistor

V+ = 7.5V

V+ = 24V

Temperature (°C)

125

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2.40

2.35

2.30

2.25

Under-Scale Current (mA)

2.20

2.15

UNDER-SCALE CURRENT vs TEMPERATURE

V+ = 7.5V to 36V

–75 –50 –25 0 25 50 75 100

Temperature (°C)

125

XTR105

SBOS061B

TYPICAL CHARACTERISTICS (Cont.)

–75 –50 –25 0 25 50 75 100

Temperature (°C)

ZERO OUTPUT CURRENT ERROR

vs TEMPERATURE

125

4
2
0

–2
–4
–6

–8
–10
–12

Zero Output Current Error (µA)

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

INPUT VOLTAGE AND CURRENT
NOISE DENSITY vs FREQUENCY

10k

1k

100

Input Voltage Noise (nV/√Hz)

10

1 10 100 1k 10k

Frequency (Hz)

INPUT BIAS AND OFFSET CURRENT

vs TEMPERATURE

25

20

15

Current Noise

Voltage Noise

ZERO OUTPUT AND REFERENCE

10k

1k

100

Input Current Noise (fA/√Hz)

10

100k

+I

B

10k

1k

100

Noise (pA/√Hz)

10

1 10 100 1k 10k

CURRENT NOISE vs FREQUENCY

Zero Output Current

Reference Current

100k

Frequency (Hz)

10

5

Input Bias and Offset Current (nA)

0

–75 –50 –25 0 25 50 75 100

INPUT OFFSET VOLTAGE DRIFT

50
45
40
35
30
25
20
15

Percent of Units (%)

10

5
0

0.2

XTR105

SBOS061B

PRODUCTION DISTRIBUTION

0.4

0.6

0.8

Input Offset Voltage Drift (µV/°C)

Temperature (°C)

Typical Production Distribution

0.1%

1.0

1.2

1.4

1.6

1.8

I

OS

of Packaged Units.

0.02%

2.0

2.2

2.4

2.6

2.8

–I

B

125

3.0

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40
35
30
25
20
15

Percent of Units (%)

10

5
0

0.025

0.050

0.075

ZERO OUTPUT DRIFT

PRODUCTION DISTRIBUTION

Typical Production Distribution

0.100

0.125

0.150

0.175

0.200

0.225

0.250

0.275

0.300

Zero Output Drift (µA/°C)

of Packaged Units.

0.325

0.350

0.375

0.400

0.425

0.450

0.475

0.500

5

TYPICAL CHARACTERISTICS (Cont.)

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

40
35
30
25
20
15

Percent of Units (%)

10

5
0

5

10152025303540455055606570

OUTPUT VOLTAGE vs V

V

REG

5.35

5.30

5.25

5.20

125°C

CURRENT SOURCE DRIFT

PRODUCTION DISTRIBUTION

Typical Production Distribution

Current Source Drift (ppm/°C)

25°C

of Packaged Units.

I

AND IR2 Included.

R1

0.04%

OUTPUT CURRENT

REG

0.01%

CURRENT SOURCE MATCHING

80
70
60
50
40
30

Percent of Units (%)

20
10

0

75

+0.05

0

–0.05

DRIFT PRODUCTION DISTRIBUTION

Typical Production Distribution

0.07%

2

4

6

8

1012141618202224262830

Current Source Matching Drift (ppm/°C)

REFERENCE CURRENT ERROR

vs TEMPERATURE

of Packaged Units.

0.02%

5.15

Output Voltage (V)

REG

V

–55°C

5.10

5.05

5.00
–1.0 –0.5 0 0.5 1.0 1.5

Output Current (mA)

V

REG

NOTE: Above 1mA,
Zero Output Degrades

2.0

–0.10

–0.15

Reference Current Error (%)

–0.20

–75 –50 –25 0 25 50 75 100 125

Temperature (°C)

6

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XTR105

SBOS061B