MAX31855:Cold-Junction Compensated Thermocouple-to-Digital Converter

Accurate Thermocouple-to-Digital Converter IC Simplifies Designs and Lowers System Cost

The MAX31855 performs cold-junction compensation and digitizes the signal from a K-, J-, N-, T-, S-, R-, or E-type thermocouple. The data is output in a signed 14-bit, SPI-compatible, read-only format. This converter resolves temperatures to 0.25°C, allows readings as high as +1800°C and as low as -270°C, and exhibits thermocouple accuracy of ±2°C for temperatures ranging from -200°C to +700°C for K-type thermocouples. For full range accuracies and other thermocouple types, see the Thermal Characteristics specifications in the full data sheet. FAQs: MAX31855

Key Features
  • Integration Reduces Design Time and Lowers System Cost
    • 14-Bit, 0.25°C Resolution Converter
    • Integrated Cold-Junction Compensation
    • Versions Available for Most Common Thermocouple Types: K-, J-, N-, T-, S-, R-, and E-Type
    • Detects Thermocouple Shorts to GND or VCC
    • Detects Open Thermocouple
  • Interfaces to Most Microcontrollers
    • Simple SPI-Compatible Interface (Read-Only)
MAX31855: Typical Application Circuit
MAX31855: Typical Application Circuit
Applications/Uses
  • Appliances
  • Automotive
  • HVAC
  • Industrial
DataSheet
titleDownload file
MAX31855 Data SheetMAX31855.pdf
Parametrics
Part NumberSensor TypeFunctionsInterfaceChannelsAccuracy
(±°C)
Parasite Pwr.Temp. Resolution
(bits)
Oper. Temp.
(°C)
Package/PinsBudgetary
Price
See Notes
MAX31855RemoteThermocouple-to-Digital ConverterSPIOne2No14-40 to +125SOIC(N)/8$3.11 @1k
Design kits & evaluation modules
Quality and Environmental Data
Related Products
  • MAX6675:Cold-Junction-Compensated K-Thermocouple-to-Digital Converter (0°C to +1024°C)
  • MAX6674:Cold-Junction-Compensated K-Thermocouple-to-Digital Converter (0°C to +128°C)
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX31855EASA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855EASA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855JASA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855JASA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855KASA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855KASA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855NASA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855NASA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855RASA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855RASA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX31855SASA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855SASA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855TASA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
MAX31855TASA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +125°CLead Free
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