Specifications

62 Control and Automation Solutions Guide
Complete Thermocouple Interface Designs Eliminate External
Components, Use Less Space
DS600, MAX1416, MAX6133, MAX31855
The thermocouple circuit shown in
Figure 1 uses the MAX1416 ADC
that allows direct interfacing with
thermocouples, thereby eliminating
external components and reducing
the overall footprint. The internal PGA
eliminates the need for an external
precision amplier; self-calibration
avoids expensive calibration procedures
during manufacture. The MAX1416
accommodates negative temperatures
because its input common-mode
range extends 30mV below ground.
Cold-junction temperature is measured
using a DS600 analog temperature
sensor located at the thermocouple
connector. With ±0.5°C accuracy, the
DS600 provides the most accurate cold-
junction compensation of any analog
temperature-sensor IC on the market.
Adding the cold-junction temperature to
the temperature measured by the ADC
corrects for the parasitic thermocouples
created when the thermocouple
connector is linked to the system.
(Continued on following page)
Figure 1. A thermocouple measurement circuit in which the MAX1416 measures the thermocouple output and the DS600 measures the
cold-junction temperature.
5V
CLKIN
RESET
CS
DIN
SCLK
DOUT
DRDY
GND
GNDCTG
GND
IN
OUT
V
DD
V
DD
V
OUT
CLKOUT
AIN1+
AIN1-
AIN2+
AIN2-
REF+
REF-
5V
5V
20pF
20pF
0.1μF
0.1μF
10μF
ECS-49-20-1
PCC-SMP-K-R
THERMO-
COUPLE
CONNECTOR
CLOSE
PROXIMITY
MAX1416
DS600
MAX6133