Cold Junction Compensator
s 80µA Supply Current
s 4V to 36V Operation
s 0.5°C Initial Accuracy (A Version)
s Compatible with Standard Thermocouples
(E, J, K, R, S, T)
s Auxiliary 10mV/°C Output
s Available in 8-Lead PDIP and SO Packages
s Thermocouple Cold Junction Compensator
s Centigrade Thermometer
s Temperature Compensation Network
The LT®1025 is a micropower thermocouple cold junction
compensator for use with type E, J, K, R, S, and T
thermocouples. It utilizes wafer level and post-package
trimming to achieve 0.5°C initial accuracy. Special curvature
correction circuitry is used to match the “bow” found in all
thermocouples so that accurate cold junction compensation
is maintained over a wider temperature range.
The LT1025 will operate with a supply voltage from 4V to 36V.
Typical supply current is 80µA, resulting in less than 0.1°C
internal temperature rise for supply voltages under 10V.
A 10mV/°C output is available at low impedance, in addition
to the direct thermocouple voltages of 60.9µV/°C (E),
51.7µV/°C (J), 40.3µV/°C (K, T) and 5.95µV/°C (R, S). All
outputs are essentially independent of power supply voltage.
A special kit is available (LTK001) which contains an LT1025
and a custom tailored thermocouple amplifier. The amplifier
and compensator are matched to allow a much tighter specifi-
cation of temperature error than would be obtained by adding
the compensator and amplifier errors on a worst-case basis.
The amplifier from this kit is available separately as LTKA0x.
The LT1025 is available in either an 8-pin PDIP or 8-pin SO
package for temperatures between 0°C and 70°C.
, LTC and LT are registered trademarks of Linear Technology Corporation.
R, S 6µV/°C
*CORRECTS FOR BOW
IN COLD JUNCTION, NOT
IN PROBE (HOT JUNCTION)
LT1025 • BD01
Type K 10mV/°C Thermometer
GND R– VO
C1 (OPEN) FOR LT1025 TEMPERATURES ≥ 0°C
0.1µF **SELECTED FOR 0°C TO 100°C RANGE
†† OR EQUIVALENT. SEE
LT1025 • TA01