AD594AD

Overview

The AD594AD is a monolithic thermocouple amplifier with cold junction compensation, designed for Type J inputs. It integrates an ice point reference and precalibrated amplifier to produce a high-level 10 mV/°C output. The device features laser wafer trimming for ±1°C calibration accuracy at +25°C. It operates on a wide power supply range from +5 V to dual supplies spanning 30 V, with typical low power consumption under 1 mW. The component includes a thermocouple failure alarm and flexible pin-strapping options for setpoint control or standalone Celsius transducer operation.

Feature Summary

• Integrates instrumentation amplifier and cold junction compensator in a single package
• Laser wafer trimmed for specific Type J thermocouple characteristics
• Includes built-in thermocouple open circuit detection alarm
• Supports linear amplification or switched setpoint controller modes

Applications

• Industrial temperature measurement systems requiring direct thermocouple interfacing
• Setpoint temperature controllers using fixed or remote voltage references
• Standalone Celsius temperature transducers utilizing internal compensation voltage

Procurement Notes

Verify the AD594AD ordering suffix indicates the A grade performance level with ±1°C calibration accuracy. Confirm the TO-116 (D-14) package type matches the required side-brazed ceramic DIP form factor. Ensure compatibility with Type J thermocouples as the device is factory trimmed for this specific alloy combination.

Selection Notes

Select the AD594AD when precise Type J thermocouple conditioning is required without external calibration components. The A grade offers tighter calibration accuracy compared to the C grade variant. Consider the TO-116 package for hermetic sealing requirements in harsh environments. Verify that the application supports the necessary supply voltage configuration for the desired temperature range.

Part Context

The AD594AD belongs to the AD594/AD595 family of monolithic thermocouple signal conditioners. This series combines amplification and cold junction compensation to simplify temperature sensing circuits. The AD594 variant is specifically calibrated for Type J thermocouples, while the AD595 serves Type K inputs. Both share identical functional architectures and pinouts.

Replacement Considerations

The AD594CD is the C grade version offering ±3°C accuracy. The AD595AD provides equivalent functionality for Type K thermocouples.