AD8497ARMZ

Overview

The AD8497ARMZ is a precision K-type thermocouple amplifier with integrated cold junction compensation, housed in an 8-lead MSOP package. It delivers a linear 5 mV/°C output voltage directly proportional to the measurement junction temperature. The device operates on a single supply ranging from 2.7 V to 36 V or dual supplies of ±2.7 V to ±18 V. It features a quiescent current of 180 μA and supports a bandwidth of 25 kHz. Initial accuracy is specified at ±1°C (Grade C) or ±3°C (Grade A), with ambient temperature rejection of 0.025°C/°C.

Feature Summary

• Integrated cold junction compensation optimized for ambient temperatures between 25°C and 100°C.
• High impedance differential inputs with overvoltage protection up to VS ± 25 V.
• Reference pin allows offset adjustment for negative temperature measurements.
• Thermocouple break detection capability via internal bias currents.

Applications

• J or K type thermocouple temperature measurement
• Setpoint controller applications
• Exhaust gas temperature sensing
• Catalytic converter temperature sensing

Procurement Notes

Verify the specific grade (A or C) required for initial accuracy specifications. Confirm that the operating environment aligns with the AD8497's optimized ambient range of 25°C to 100°C. Ensure the reference junction is physically close to the device to maintain compensation accuracy. Check datasheet limits for supply voltage and input common-mode ranges before integration.

Selection Notes

Select the AD8497 specifically for K-type thermocouples requiring operation in elevated ambient environments. Compare against AD8495 if the application operates in standard laboratory conditions near 25°C. Consider the fixed gain architecture which simplifies design but limits flexibility compared to programmable amplifiers. Verify power supply constraints against the wide input voltage range capabilities.

Part Context

The AD8497 is part of the AD8494/AD8495/AD8496/AD8497 family of precision thermocouple signal conditioners. While sharing the same package and core architecture, it is distinctively laser-trimmed for K-type thermocouples and optimized for higher ambient temperatures than the AD8495. This differentiation ensures accurate cold junction compensation in industrial settings like ovens or automotive exhaust systems.

Replacement Considerations

The AD8495ARMZ serves as a functional substitute for K-type applications but is optimized for lower ambient temperatures (0°C to 50°C). Substitution requires verification that the ambient temperature range meets the AD8495 specifications. No other direct replacements are documented in the provided source material.