Cold-Junction Compensated, 1-Wire Thermocouple-to-Digital Converters

Accurate 1-Wire Thermocouple-to-Digital Converter ICs Ease Design Effort and Lower System Cost


The MAX31850/MAX31851 cold-junction compensated, 1-Wire® thermocouple-to-digital converters perform cold-junction compensation and digitize the signal from a K-, J-, N-, T-, S-, R-, or E-type thermocouple. The converters resolve temperatures to 0.25°C, allow readings as high as +1768°C and as low as -270°C, and exhibit thermocouple accuracy of 8 LSBs (2°C) for temperatures ranging from -200°C to +700°C.

Communication with the master microcontroller is over a 1-Wire bus that by definition requires only one data line (and ground) for communication. Operating power can be obtained directly from the data line (“parasite power”), eliminating the need for an external power supply.

Each device has a unique 64-bit serial code, which allows multiple units to function on the same 1-Wire bus. Therefore, it is simple to use one microcontroller (the master device) to monitor temperature from many thermocouples distributed over a large area.

Four location address inputs simplify mapping of individual units to specific locations.

MAX31850, MAX31851: Block Diagram MAX31850, MAX31851: Block Diagram Enlarge+

Key Features

  • Integration Reduces Design Time and Lowers System Cost
    • 14-Bit, 0.25°C Resolution
    • Integrated Cold-Junction Compensation
    • Available for Multiple Thermocouples Types: Supports K-, J-, N-, T-, and E-Type (MAX31850); S- and R-Type (MAX31851)
    • Detects Thermocouple Shorts to GND or VDD
    • Detects Open Thermocouple
  • 1-Wire Multiddrop Capability Simplifies Multisensor Systems
    • 1-Wire Interface (Read-Only); Power Can Be Obtained from Interface (Parasite-Powered Mode)


  • Appliances
  • HVAC
  • Industrial
  • Medical
Part Number Sensor Type Functions Interface Channels Accuracy
Parasite Pwr. Temp. Resolution
Oper. Temp.
Package/Pins Budgetary
See Notes
MAX31850  Remote Thermocouple-to-Digital Converter 1-Wire One 2 Yes 14 -40 to +125
$3.10 @1k
See All Temperature Sensors (112)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX31850EVKIT: Evaluation Kit for the MAX31850 and MAX31851

Quality and Environmental Data

Product Reliability Reports: MAX31850.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Tools & Models


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