The AD592 is a two terminal monolithic integrated circuit temperature
transducer that provides an output current proportional
to absolute temperature. For a wide range of supply
voltages the transducer acts as a high impedance temperature
dependent current source of 1 mA/K. Improved design and laser
wafer trimming of the IC’s thin film resistors allows the AD592
to achieve absolute accuracy levels and nonlinearity errors previously
unattainable at a comparable price.
The AD592 can be employed in applications between –25°C
and +105°C where conventional temperature sensors (i.e., thermistor,
RTD, thermocouple, diode) are currently being used.
The inherent low cost of a monolithic integrated circuit in a
plastic package, combined with a low total parts count in any
given application, make the AD592 the most cost effective temperature
transducer currently available. Expensive linearization
circuitry, precision voltage references, bridge components, resistance
measuring circuitry and cold junction compensation are
not required with the AD592.
Typical application areas include: appliance temperature sensing,
automotive temperature measurement and control, HVAC
(heating/ventilating/air conditioning) system monitoring, industrial
temperature control, thermocouple cold junction compensation,
board-level electronics temperature diagnostics,
temperature readout options in instrumentation, and temperature
correction circuitry for precision electronics. Particularly
useful in remote sensing applications, the AD592 is immune to
voltage drops and voltage noise over long lines due to its high
impedance current output. AD592s can easily be multiplexed;
the signal current can be switched by a CMOS multiplexer or
the supply voltage can be enabled with a tri-state logic gate.
The AD592 is available in three performance grades: the
AD592AN, AD592BN and AD592CN. All devices are packaged
in a plastic TO-92 case rated from –45°C to +125°C. Performance
is specified from –25°C to +105°C. AD592 chips are
also available, contact the factory for details.