ADI AD597ARZ

The AD596/AD597 is a monolithic temperature setpoint controller that has been optimized for use at elevated temperatures such as those found in oven control applications. The device cold junction compensates and amplifies a type J or K thermocouple input to derive an internal signal proportional to temperature. The internal signal is then compared with an externally applied setpoint voltage to yield a low impedance switched output voltage. Dead-Band or switching hysteresis can be programmed using a single external resistor. Alternately, the AD596/AD597 can be configured to provide a voltage output (10mV / °C) directly from a type J or K thermocouple signal. It can also be used as a stand-alone voltage-output temperature sensor. The AD596/AD597 can be powered with a single supply from +5V to +30V or dual supplies up to a total span of 36 V. Typical quiescent supply current is 160μA, which minimizes self-heating errors. The AD596/AD597 H package option includes a thermocouple failure alarm that indicates an open thermocouple lead when operated in the temperature proportional measurement mode. The alarm output has a flexible format which can be used to drive relays, LEDs or TTL logic. The device is packaged in a reliability qualified, cost effective 10-pin metal can or SOIC and is trimmed to operate over an ambient temperature range from +25°C to +100°C. Operation over an extended ambient temperature range is possible with slightly reduced accuracy. The AD596 will amplify thermocouple signals covering the entire -200°C to +760°C temperature range recommended for type J thermocouples while the AD597 can accommodate -200°C to +1250°C type K inputs. The AD596/AD597 has a calibration accuracy of ±4°C at an ambient temperature of 60°C and an ambient temperature stability specification of 0.05°C / °C from +25°C to +100°C. If higher accuracy, or a lower ambient operating temperature is required, either the AD594 (J thermocouple) or AD595 (K thermocouple) should be considered.

• Low Cost
• Operates with Type J (AD596) or Type K (AD597) Thermocouples
• Built-In Ice Point Compensation
• Temperature Proportional Operation - 10 mV/°C
• Temperature Setpoint Operation - ON/OFF
• Programmable Switching Hysteresis
• High Impedance Differential Input
• The AD596/AD597 provides cold junction compensation and a high gain amplifier which can be used as a setpoint comparator.
• The input stage of the AD596/AD597 is a high quality instrumentation amplifier that allows the thermocouple to float over most of the supply voltage range.
• Linearization not required for thermocouple temperatures close to 175°C (+100°C to +540°C for AD596).
• Cold junction compensation is optimized for ambient temperatures ranging from +25°C to +100°C.
• In the stand-alone mode, the AD596/AD597 produces an output voltage that indicates its own temperature.