XTR105
XTR
105
XTR
105
SBOS061B – FEBRUARY 1997 – REVISED AUGUST 2004
4-20mA CURRENT TRANSMITTER
with Sensor Excitation and Linearization
FEATURES
q
LOW UNADJUSTED ERROR
q
TWO PRECISION CURRENT SOURCES: 800
µ
A each
q
LINEARIZATION
q
2- OR 3-WIRE RTD OPERATION
q
LOW OFFSET DRIFT: 0.4
µ
V/
°
C
q
LOW OUTPUT CURRENT NOISE: 30nA
PP
q
HIGH PSR: 110dB minimum
q
HIGH CMR: 86dB minimum
q
WIDE SUPPLY RANGE: 7.5V to 36V
q
DIP-14 AND SO-14 PACKAGES
Nonlinearity (%)
APPLICATIONS
q
INDUSTRIAL PROCESS CONTROL
q
FACTORY AUTOMATION
q
SCADA REMOTE DATA ACQUISITION
q
REMOTE TEMPERATURE AND PRESSURE
TRANSDUCERS
Pt100 NONLINEARITY CORRECTION
USING XTR105
5
4
3
2
1
0
−1
−200°C
Process Temperature (°C)
+850°C
DESCRIPTION
The XTR105 is a monolithic 4-20mA, 2-wire current transmit-
ter with two precision current sources. It provides complete
current excitation for platinum RTD temperature sensors and
bridges, instrumentation amplifiers, and current output cir-
cuitry on a single integrated circuit.
Versatile linearization circuitry provides a 2nd-order correc-
tion 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 un-
adjusted error of the complete current transmitter is low
enough to permit use without adjustment in many applica-
tions. This includes zero output current drift, span drift, and
nonlinearity. The XTR105 operates on loop power-supply
voltages down to 7.5V.
The XTR105 is available in DIP-14 and SO-14 surface-
mount packages and is specified for the –40°C to +85°C
industrial temperature range.
Uncorrected
RTD Nonlinearity
Corrected
Nonlinearity
I
R
= 0.8mA
I
R
= 0.8mA
V
LIN
V
REG
+
7.5V to 36V
V
PS
4-20 mA
RTD
R
G
XTR105
V
O
R
L
–
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
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testing of all parameters.
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