LTK001
Thermocouple Cold Junction
Compensator and
Matched Amplifier
thermocouple applications. It has low supply current to
minimize warmup drift, very low offset voltage (<35µV),
high gain, and extremely low input bias currents (<600pA)
to allow high impedance input filters to be used without
degrading offset voltage or drift.
FEATURES
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0.75°C Initial Accuracy (A Version)
Extremely Low Warmup Drift
Preset Outputs for Type E, J, K, R, S, T
Single 5V to ± 20V Operation
480µA Typical Supply Current
Available in 8-Pin DIP Package
Matching of the kits is accomplished by separating the
compensators and amplifiers according to the polarity of
their initial (room temperature) errors. This eliminates the
need to sum the errors of the two components to find the
worst-case error.
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APPLICATIO S
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The LTK001 has direct thermocouple outputs of
60.9µV/°C (E), 51.7µV/°C (J), 40.6µV/°C (K, T), and
5.95µV/°C (R, S). It also has a 10mV/°C output which can
be scaled to match any arbitrary thermocouple.
Thermocouple Cold Junction Compensation
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DESCRIPTIO
The LTK001 is a thermocouple amplifier supplied with a
matched cold junction compensator. By separating the
amplifier and compensator functions, the problem of
compensator temperature rise is virtually eliminated. The
compensator is a selected version of the LT®1025 cold
junction compensator. The amplifier, which is also available separately as LTKA0x has been specially selected for
For multiple thermocouple applications using one compensator, amplifiers may be ordered separately (LTKA0x),
still matched to the compensator.
, LTC and LT are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. For typical performance curves and
applications circuits consult the LT1025 data sheet.
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TYPICAL APPLICATIO
Type K 10mV/°C Thermometer
R2
100Ω
FULL-SCALE TRIM
R3**
255k
1%
C2
0.1µF
R1
1k
1%
V+
V+
–
LTKA0x
VIN
K
–
LT1025
GND
*
+
C1
0.1µF
+
VOUT
10mV/°C
V–
TYPE K
V0
R–
R4*
V–
–
*R4 ≤ V , R4 IS NOT REQUIRED (OPEN) FOR
30µA
LT1025 TEMPERATURES ≥ 0°C.
**SELECTED FOR 0°C–100°C RANGE
LTK001 TA01
001fa
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