MAX31856:Precision Thermocouple to Digital Converter with Linearization

Simplifies Thermocouple Designs with Integrated Automatic Cold Junction Compensation and Linearization Correction

The MAX31856 performs cold-junction compensation and digitizes the signal from any type of thermocouple. The output data is formatted in degrees Celsius. This converter resolves temperatures to 0.0078125°C, allows readings as high as +1800°C and as low as -210°C (depending on thermocouple type), and exhibits thermocouple voltage measurement accuracy of ±0.15%. The thermocouple inputs are protected against overvoltage conditions up to ±45V. A lookup table (LUT) stores linearity correction data for several types of thermocouples (K, J, N, R, S, T, E, and B). Line frequency filtering of 50Hz and 60Hz is included, as is thermocouple fault detection. A SPI-compatible interface allows selection of thermocouple type and setup of the conversion and fault detection processes.

Key Features
  • Provides High-Accuracy Thermocouple Temperature Readings
    • Includes Automatic Linearization Correction for 8 Thermocouple Types
    • ±0.15% (max, -20°C to +85°C) Thermocouple Full-Scale and Linearity Error
    • 19-Bit, 0.0078125°C Thermocouple Temperature Resolution
  • Internal Cold-Junction Compensation Minimizes System Components
    • ±0.7°C (max, -20°C to +85°C) Cold-Junction Accuracy
  • ±45V Input Protection Provides Robust System Performance
  • Simplifies System Fault Management and Troubleshooting
    • Detects Open Thermocouples
    • Over- and Undertemperature Fault Detection
  • 50Hz/60Hz Noise Rejection Filtering Improves System Performance
  • 14-Pin TSSOP Package
MAX31856: Block Diagram
MAX31856: Block Diagram
Applications/Uses
  • Industrial Equipment
  • Industrial Ovens, Furnaces, and Environmental Chambers
  • Temperature Controllers
DataSheet
titleDownload file
MAX31856 Data SheetMAX31856.pdf
Parametrics
Part NumberSensor TypeFunctionsInterfaceChannelsAccuracy
(±°C)
Parasite Pwr.Temp. Resolution
(bits)
Oper. Temp.
(°C)
Package/PinsBudgetary
Price
See Notes
MAX31856RemoteThermocouple-to-Digital Converter3-Wire/SPIOne1.5No19-55 to +125TSSOP/14$3.80 @1k
Design kits & evaluation modules
Quality and Environmental Data
Related Products
  • MAX31855:Cold-Junction Compensated Thermocouple-to-Digital Converter
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX31856MUD+ActiveTSSOP,;14 pin;33.4 mm²-55°C to +125°CLead Free
MAX31856MUD+TActiveTSSOP,;14 pin;33.4 mm²-55°C to +125°CLead Free
MAX31856PMB1#ActiveEVKIT;0°C to +70°CSee data sheet
MAX31856.pdf MAX31856
MAX31856_cn.pdf MAX31856
MAX31856.pdf MAX31856
MAX31856.pdf MAX31856
MAX31856.pdf MAX31856
MAX31856.pdf MAX31856