The MAX31856 is a sophisticated thermocouple-to-digital converter with a built-in 19-bit analog-to-digital converter (ADC). Internal functions include correction for thermocouple nonlinearity, input protection, cold-junction compensation sensing and correction, a digital controller, a SPI-compatible interface, and associated control logic. The temperature conversion process consists of five steps: The input amplifier and ADC amplify digitize the thermocouple’s voltage output. The internal temperature sensor measures  the cold-junction temperature. Using the internal lookup table (LUT), the ADC code corresponding to the cold junction temperature for the selected thermocouple type is determined. The thermocouple code and the cold-junction code are summed to produce the code corresponding to the cold-junction compensated thermocouple temperature. Finally, the LUT is used to produce a cold-junction compensated output code in units of °C. However, the MAX31856 users do not need to worry about all of that, as it is done automatically.