The MAX31856 performs cold-junction compensation and digitizes the signal from any type of thermocouple. The output data is in degrees Celsius. This converter has a temperature resolution of 0.0078125°C, a measurement range up to +1800°C and down to -210°C (depending on the thermocouple type), and a thermocouple voltage measurement accuracy of ±0.15%. The thermocouple input features overvoltage protection up to ±45V. A look-up table (LUT) stores linear correction data for several thermocouple types (K, J, N, R, S, T, E, and B). The device integrates 50Hz and 60Hz power-line filtering functions, and also features thermocouple fault detection functionality. An SPI-compatible interface can be used to select the thermocouple type and configure the conversion and fault detection processes.

Product Features Provides high-precision thermocouple temperature readings Includes automatic linear correction for 8 thermocouple types Thermocouple full-scale and linearity error is ±0.15% (maximum, -20°C to +85°C) 19-bit resolution, thermocouple temperature resolution is 0.0078125°C Internal cold-junction compensation reduces the number of system components Cold-junction accuracy is ±0.7°C (maximum, -20°C to +85°C) ±45V input protection ensures stable system performance Simplifies system fault management and troubleshooting Detects thermocouple open-circuit faults Over-temperature and under-temperature fault detection 50Hz/60Hz noise suppression filtering function can improve system performance Uses 14-pin TSSOP package