AD590

Features:

·Linear current output: 1 µA/K
·Wide temperature range: −55°C to +150°C
·Probe compatible ceramic sensor package
·2-terminal device: voltage in/current out
·Laser trimmed to ±0.5°C calibration accuracy (AD590M)
·Excellent linearity: ±0.3°C over full range (AD590M)
·Wide power supply range: 4 V to 30 V
·Sensor isolation from case
·Low cost




Pinout






Specifications

Parameter Forward Voltage ( E+ or E) Reverse Voltage (E+ to E) Breakdown Voltage (Case E+ or E) Rated Performance Temperature Range1 Storage Temperature Range1 Lead Temperature (Soldering, 10 sec)

Rating 44 V −20 V ±200 V −55 to +150 −65 to +155 300

Description

The AD590 is a 2-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 298.2 K (25).

The AD590 should be used in any temperature-sensing application below 150 in 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 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 at hundreds of feet from thereceiving 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.