A mixed-signal integrated circuit comprises: 1) an analog front end having differential inputs adapted for directly connecting to at least one thermocouple, 2) an analog-to-digital (ADC) for converting the thermocouple voltages to digital representations thereof, 3) a linearization circuit capable of performing the multi-order polynomial equations for converting the thermocouple electromotive voltages (the digital representations) to linear temperature measurement units by using coefficients unique to each type of thermocouple from a coefficients table based upon the National Institute of Standards and Technology (NIST), 4) a integrated temperature sensor for measuring cold junction temperature, 5) optionally, an input multiplexer for selecting each of a plurality of thermocouples for measurement thereof, 6) optionally, registers for storing measured temperature values, high and low set points, alarm limits, etc., and 7) a communications interface for setting parameters and receiving temperature information.