Patent ID: 8485724

Claim:
A mixed-signal integrated circuit for converting thermocouple electromotive force voltages to temperature values and having integrated cold-junction compensation and linearization, comprising: an analog-to-digital converter (ADC) having an analog input operable to be coupled to a thermocouple; linearization logic coupled to a digital output of the ADC; a nonvolatile memory storing a table of NIST coefficients for the thermocouple, wherein the linearization logic is coupled to the nonvolatile memory and uses coefficients from the NIST coefficient table when solving for a polynomial equation associated with linearization of the thermocouple voltages; an integrated cold junction temperature sensor; a cold junction temperature sensor interface for converting temperature of the cold junction temperature sensor into digital cold junction temperature values; a digital summer for adding the digital cold junction temperature values to the linearized digital temperature values from the linearization logic for providing cold junction temperature compensated digital temperature values normalized to a temperature base; data acquisition and control logic coupled to an output of the digital summer for receiving the normalized cold junction temperature compensated digital temperature values and making available those normalized cold junction temperature compensated digital temperature values available to an external system; and an integrated circuit package for the mixed-signal integrated circuit designed to be thermally coupled to a isothermal connection block of the thermocouple.