ADI AD8495CRMZ

The AD8494/AD8495/AD8496/AD8497 are precision instrumentation amplifiers with thermocouple cold junction compensators on an integrated circuit. They produce a high level (5 mV/°C) output directly from a thermocouple signal by combining an ice point reference with a precalibrated amplifier. They can be used as standalone thermometers or as switched output setpoint controllers using a fixed or remote setpoint control. The AD8494/AD8495/AD8496/AD8497 can be powered from a single-ended supply (less than 3 V) and can measure temperatures below 0°C by offsetting the reference input. To minimize selfheating, an unloaded AD849x typically operates with a total supply current of 180 μA, but it is also capable of delivering in excess of ±5 mA to a load. The AD8494 and AD8496 are precalibrated by laser wafer trimming to match the characteristics of J type (iron - constantan) thermocouples; the AD8495 and AD8497 are laser trimmed to match the characteristics of K type (chromel - alumel) thermocouples. The AD8494/AD8495/AD8496/AD8497 allow a wide variety of supply voltages. With a 5 V single supply, the 5 mV/°C output allows the devices to cover nearly 1000 degrees of a thermocouple’s temperature range. The AD8494/AD8495/AD8496/AD8497 work with 3V supplies, allowing them to interface directly to lower supply ADCs. They can also work with supplies as large as 36 V in industrial systems that require a wide common - mode input range.

• Low cost and easy to use
• Pretrimmed for J or K type thermocouples
• Internal cold junction compensation
• High impedance differential input
• Standalone 5 mV/°C thermometer
• Reference pin allows offset adjustment
• Thermocouple break detection
• Laser wafer trimmed to ±1°C initial accuracy and 0.025°C/°C ambient temperature rejection
• Low power: < 1 mW at VS = 5 V
• Wide power supply range Single supply: 2.7 V to 36 V Dual supply: ±2.7 V to ±18 V
• Small, 8 - lead MSOP

• J or K type thermocouple temperature measurement
• Setpoint controller
• Celsius thermometer
• Universal cold junction compensator
• White goods (oven, stovetop) temperature measurements
• Exhaust gas temperature sensing
• Catalytic converter temperature sensing