Analog Devices AD592 a Datasheet
Low Cost, Precision IC
a
FEATURES
High Precalibrated Accuracy: 0.58C max @ +258C
Excellent Linearity: 0.158C max (08C to +708C)
Wide Operating Temperature Range: –258C to +1058C
Single Supply Operation: +4 V to +30 V
Excellent Repeatability and Stability
High Level Output: 1 mA/K
Two Terminal Monolithic IC: Temperature In/
Current Out
Minimal Self-Heating Errors
PRODUCT DESCRIPTION
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 µA/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.
*Protected by Patent No. 4,123,698.
Temperature Transducer
AD592*
CONNECTION DIAGRAM
PIN 3 PIN 2 PIN 1
(–) (NC) (+)
PIN 2 CAN BE EITHER ATTACHED OR UNCONNECTED
*
PRODUCT HIGHLIGHTS
1. With a single supply (4 V to 30 V) the AD592 offers
0.5°C temperature measurement accuracy.
2. A wide operating temperature range (–25°C to +105°C)
and highly linear output make the AD592 an ideal substitute for older, more limited sensor technologies (i.e.,
thermistors, RTDs, diodes, thermocouples).
3. The AD592 is electrically rugged; supply irregularities
and variations or reverse voltages up to 20 V will not
damage the device.
4. Because the AD592 is a temperature dependent current
source, it is immune to voltage noise pickup and IR
drops in the signal leads when used remotely.
5. The high output impedance of the AD592 provides
greater than 0.5°C/V rejection of supply voltage drift and
ripple.
6. Laser wafer trimming and temperature testing insures
that AD592 units are easily interchangeable.
7. Initial system accuracy will not degrade significantly over
time. The AD592 has proven long term performance
and repeatability advantages inherent in integrated circuit design and construction.
378
343
– µA
OUT
I
273
248
–45 –25 0 +70 +105 +125
BOTTOM VIEW
1µA/oK
TEMPERATURE –
o
C
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
AD592–SPECIFICATIONS
(typical @ TA = +258C, VS = +5 V, unless otherwise noted)
AD592AN AD592BN AD592CN
Model Min Typ Max Min Typ Max Min Typ Max Units
ACCURACY
Calibration Error @ +25°C
T
= 0°C to +70°C
A
Error over Temperature 1.8 3.0 0.8 1.5 0.4 0.8 °C
Nonlinearity
T
= –25°C to +105°C
A
Error over Temperature
Nonlinearity
2
2
1
1.5 2.5 0.7 1.0 0.3 0.5 °C
0.15 0.35 0.1 0.25 0.05 0.15 °C
3
2.0 3.5 0.9 2.0 0.5 1.0 °C
0.25 0.5 0.2 0.4 0.1 0.35 °C
OUTPUT CHARACTERISTICS
Nominal Current Output
@ +25°C (298.2K) 298.2 298.2 298.2 µA
Temperature Coefficient 1 1 1 µA/°C
Repeatability
Long Term Stability
4
5
0.1 0.1 0.1 °C
0.1 0.1 0.1 °C/month
ABSOLUTE MAXIMUM RATINGS
Operating Temperature –25 +105 –25 +105 –25 +105 °C
Package Temperature
6
–45 +125 –45 +125 –45 +125 °C
Forward Voltage (+ to –) 44 44 44 V
Reverse Voltage (– to +) 20 20 20 V
Lead Temperature
(Soldering 10 sec) 300 300 300 °C
POWER SUPPLY
Operating Voltage Range 4 30 4 30 4 30 V
Power Supply Rejection
+4 V < V
+5 V < V
+15 V < V
NOTES
1
An external calibration trim can be used to zero the error @ +25° C.
2
Defined as the maximum deviation from a mathematically best fit line.
3
Parameter tested on all production units at +105°C only. C grade at –25°C also.
4
Maximum deviation between +25°C readings after a temperature cycle between –45°C and +125°C. Errors of this type are noncumulative.
5
Operation @ +125°C, error over time is noncumulative.
6
Although performance is not specified beyond the operating temperature range, temperature excursions within the package temperature range will not damage the device.
Specifications subject to change without notice.
Specifications shown in boldface are tested on all production units at final electrical test. Results from those tests are used to calculate outgoing quality levels. All min
and max specifications are guaranteed, although only those shown in boldface are tested on all production units.
< +5 V 0.5 0.5 0.5 °C/V
S
< +15 V 0.2 0.2 0.2 °C/V
S
< +30 V 0.1 0.1 0.1 °C/V
S
TEMPERATURE SCALE CONVERSION EQUATIONSMETALIZATION DIAGRAM
66MILS
V+
42MILS
V–
8C =
8F =
5
(8F –32)
9
9
8C +32
5
K = °C +273.15
°R = °F +459.7
ORDERING GUIDE
Max Cal Max Error Max Nonlinearity Package
Model Error @ +258C –258C to +1058C –258C to +1058C Option
AD592CN 0.5°C 1.0°C 0.35°C TO-92
AD592BN 1.0°C 2.0°C 0.4°C TO-92
AD592AN 2.5°C 3.5°C 0.5°C TO-92
–2–
REV. A
Typical @ VS = +5 V
TOTAL ERROR –
o
C
TEMPERATURE – oC
–25 0 +25 +70 +105
+2.0
+1.5
+1.0
+0.5
0
–0.5
–1.0
–1.5
–2.0
0.75
0.50
0.25
0
–0.25
–0.50
–0.75
0 500 1000 1500 2000
TIME – Hours
TOTAL ERROR –
o
C
+2.0
+1.5
+1.0
C
o
+0.5
0
–0.5
TOTAL ERROR –
–1.0
–1.5
–2.0
–25 0 +25 +70 +105
Typical Performance Curves–AD592
TEMPERATURE – oC
AD592CN Accuracy Over Temperature
+2.0
+1.5
+1.0
C
o
+0.5
0
–0.5
TOTAL ERROR –
–1.0
–1.5
–2.0
–25 0 +25 +70 +105
TEMPERATURE –
o
C
AD592AN Accuracy Over Temperature
0.75
AD592BN Accuracy Over Temperature
Long-Term Stability @ +85°C and 85% Relative Humidity
REV. A
0.50
C
0.25
o
0
–0.25
TOTAL ERROR –
–0.50
–0.75
0 500 1000 1500 2000
TIME – Hours
Long-Term Stability @ +125°C
–3–
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