Product Details
●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 either 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 self-heating, 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) thermo-couples. See Table 1 on the data sheet for the optimized ambient temperature range of each part.
●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 thermo-couple’s temperature range.
●The AD8494/AD8495/AD8496/AD8497 work with 3 V 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.
●Product Highlights
● 1. Complete, precision laser wafer trimmed thermocouple signal conditioning system in a single IC package.
● 2. Flexible pinout provides for operation as a setpoint controller or as a standalone Celsius thermometer.
● 3. Rugged inputs withstand 4 kV ESD and provide over-voltage protection (OVP) up to VS ± 25 V.
● 4. Differential inputs reject common-mode noise on the thermocouple leads.
● 5. Reference pin voltage can be offset to measure 0°C on single supplies.
● 6. Available in a small, 8-lead MSOP that is fully RoHS compliant.
●Applications
● J type thermocouple temperature measurement
● Setpoint controller
● Celsius thermometer
● Universal cold junction compensator
● White goods (oven, stove top) temperature measurements
● Exhaust gas temperature sensing
● Catalytic converter temperature sensing
●### Features and Benefits
● Low cost and easy to use
● Pretrimmed for J type thermocouples
● Internal cold junction compensation
● High impedance differential input
● Standalone 5 mV/°C thermometer
● Reference pin allows offset adjustment
● Thermocouple break detection
● See data sheet for additional features.
