The unloaded AD849x typically operates with a total supply current of 180μA to minimize self-heating, but it is also capable of delivering in excess of ±5mA 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 supports a wide variety of supply voltages. Using a 5V single supply, the 5mV/°C output allows the devices to cover nearly 1000 degrees of a thermocouple’s temperature range. The devices also work with 3V supplies, allowing them to interface directly to lower supply ADCs. The AD849x Amplifiers also can work with supplies as large as 36V in industrial systems that require a wide common-mode input range.
Additional product highlights include a complete precision laser wafer trimmed thermocouple signal conditioning system combined in a single IC package. The AD849x offers a flexible pinout providing operation as a setpoint controller or as a standalone Celsius thermometer. Rugged inputs withstand 4kV ESD and provide overvoltage protection (OVP) up to VS ± 25V, and differential inputs reject common-mode noise on the thermocouple leads.
The AD8494 is a full J-type range 0° to 50° Thermocouple Amplifier including Cold Junction Compensation.