Micropower Thermocouple Cold Junction Compensator

The AC1226 is a micropower thermocouple cold junction compensator for use with type E, J, K, R, S, and T thermocouples. It utilizes wafer level and post-packaging trimming to achieve typical 0.5°C initial accuracy. Special curvature corrective circuitry is used to match the "bow" found in all thermocouples so that accurate cold junction compensation is maintained over a wider temperature range.

The AC1226 will operate with a supply voltage from 4V to 36V. Typical supply current is 80uA, resulting in less that 0.1°C internal temperature rise for supply voltages under 10V. A 10mV/°C output is available at low impedance in addition to the direct thermocouple voltages of 60.9uV/°C (E), 51.7uV/°C (J), 40.3uV/°C (K,T), and 5.95 uV/°C (R, S). All outputs are essentially independent of power supply voltage.

The AC1226 is available in an 8-pin plastic mini-DIP for temperatures between 0 and +70°C.

* 80uA Supply Current * 4V to 36V Operation * 0.5°C Typical Initial Accuracy