Application Notes

This cookbook design describes a temperature measurement circuit with two thermocouples using the ADS1118. Thermocouple voltage measurements are made with the ADS1118 internal voltage reference, while cold-junction compensation (CJC) measurements are made with the onboard temperature sensor. Two channels of the ADC are used for two K-type thermocouples with a temperature measurement range from –270°C to 1370°C. Included in this design are ADC register settings to configure the device and pseudo code is provided to configure and read from the device. This circuit can be used in applications such as analog input modules for PLCs, lab instrumentation, and factory automation.