AD590AN Temperature Sensor

 The device is insensitive to voltage drops over long lines due to its high impedance current output.

The AD590 is a two-terminal integrated circuit temperature transducer that produces an output current proportional to absolute temperature. For supply voltages between +4 V and +30 V the device acts as a high impedance, constant current regulator passing 1 µA/K. Laser trimming of the chip’s thin-film resistors is used to calibrate the device to 298.2 µA output at 298.2K (+25°C). The AD590 should be used in any temperature sensing application below +150°Cin which conventional electrical temperature sensors are currently employed. The inherent low cost of a monolithic integrated circuit combined with the elimination of support circuitry makes the AD590 an attractive alternative for many temperature measurement situations. Linearization circuitry, precision voltage amplifiers, resistance measuring circuitry and cold junction compensation are not needed in applying the AD590. In addition to temperature measurement, applications include temperature compensation or correction of discrete components, biasing proportional to absolute temperature, flow rate measurement, level detection of fluids and anemometry. The AD590 is available in chip form making, it suitable for hybrid circuits and fast temperature measurements in protected environments. The AD590 temperature Sensor is particularly useful in remote sensing applications. The device is insensitive to voltage drops over long lines due to its high impedance current output. Any well insulated twisted pair is sufficient for operation hundreds of feet from the receiving circuitry. The output characteristics also make the AD590 easy to multiplex: the current can be switched by a CMOS multiplexer or the supply voltage can be switched by a logic gate output.

Features of AD590AN Temperature Sensor

• Linear Current Output : 1 mA/K

• Wide Range : –558C to +1508C

• Probe Compatible Ceramic Sensor Package

• Two Terminal Device : Voltage In/Current Out

• Laser Trimmed to 60.58C Calibration Accuracy (AD590M)

• Excellent Linearity : 60.38C Over Full Range (AD590M)

• Wide Power Supply Range : +4 V to +30 V

• Sensor Isolation from Case

• Low Cost