AD594CQ

The AD594CQ is an Instrumentation Amplifier with thermocouple cold junction compensator on a monolithic chip. It combines an ice point reference with a pre-calibrated amplifier to produce a high level (10mV/°C) output directly from a thermocouple signal. The AD595 includes a thermocouple failure alarm that indicates if one or both thermocouple leads become open. The alarm output has a flexible format which includes TTL drive capability. The AD595 is laser trimmed for type K (chromel-alumel) inputs. The temperature transducer voltages and gain control resistors are available at the package pins so that the circuit can be recalibrated for the thermocouple types by the addition of two or three resistors. These terminals also allow more precise calibration for both thermocouple and thermometer applications. It can be used to amplify its compensation voltage directly, thereby converting it to a stand-alone Celsius transducer with a low impedance voltage output.

• Pretrimmed for Type J
• Can be used with type T thermocouple inputs
• 10mV/°C Low impedance voltage output
• Built-in ice point compensation
• <1mW Typical low power
• Laser wafer trimmed to 1°C Calibration accuracy
• Self-contained Celsius thermometer operation
• High impedance differential input
• Differential input rejects common-mode noise voltage on the thermocouple leads
• Operation at remote application sites is facilitated by low quiescent current