The AD594/AD595 is a monolithic thermocouple amplifier with cold junction compensation, low power consumption and low output impedance.
The AD594 and AD595 integrate a cold‑junction compensator, precision amplifier and output buffer in a single IC. They are pre‑trimmed for Type J (AD594) or Type K (AD595) thermocouples, can also be used with Type T, and provide a low‑impedance 10 mV/°C voltage output. Pin‑strapping options allow operation as a linear amplifier‑compensator or as a set‑point controller, and an integrated thermocouple‑failure alarm offers TTL‑compatible signaling.
The devices operate from a single supply (+5 V to +15 V) or dual supplies up to ±30 V, draw less than 1 mW typical power, and feature selectable performance grades (C and A) with calibration accuracies of ±1 °C or ±3 °C. Detailed specifications include gain, input ranges, quiescent currents, and package options (14‑pin side‑braced DIP or low‑cost Cerdip). Recalibration procedures are provided for alternative thermocouple types such as Type E.
| Supply Voltage Range | +5 V to +15 V |
|---|---|
| Low Power Consumption | <1 mW typical |
| Operating Temperature Range | -55 °C to +125 °C |
| Closed‑Loop Gain (AD594) | 193.4 |
| Output Voltage per °C | 10 mV/°C |
The device provides a low‑impedance output of 10 mV for each degree Celsius.
Yes, it includes a thermocouple failure alarm with a flexible TTL‑drive output format.
They can be powered from a single supply of +5 V to +15 V, or from dual supplies spanning up to ±30 V.