AD592 (Rev. B)
Document overview
- Manufacturer or author: Analog Devices, Inc.
- PDF pages: 9
Technical content
(–) (NC) (+) PIN 2 CAN BE EITHER ATTACHED OR UNCONNECTED BOTTOM VIEW* REV. 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. a AD592 Tel: Fax: Low Cost, Precision IC Temperature Transducer
FEATURES
High Precalibrated Accuracy: 0.5 8C max @ +25 8C Excellent Linearity: 0.158 C max (0 8C to +70 8C) Wide Operating Temperature Range: –258 C to +105 8C 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 tem- perature transducer that provides an output current propor- tional 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 previ- ously unattainable at a comparable price. The AD592 can be employed in applications between –25 °C and +105°C where conventional temperature sensors (i.e., ther- mistor, 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 tem- perature transducer currently available. Expensive linearization circuitry, precision voltage references, bridge components, resis- tance measuring circuitry and cold junction compensation are not required with the AD592. Typical application areas include: appliance temperature sens- ing, automotive temperature measurement and control, HVAC (heating/ventilating/air conditioning) system monitoring, indus- trial temperature control, thermocouple cold junction compen- sation, board-level electronics temperature diagnostics, temperature readout options in instrumentation, and tempera- ture 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 pack- aged in a plastic TO-92 case rated from –45 °C to +125°C. Per- formance is specified from –25 °C to +105°C. AD592 chips are also available, contact the factory for details. 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 sub- stitute 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 cir- cuit design and construction. 378 343 273 248 1µA/oK –45 –25 0 +70 +105 +125 TEMPERATURE – oC IOUT – µA B 781/461-3113 781/329-4700
AD592–SPECIFICATIONS AD592AN AD592BN AD592CN Model Min Typ Max Min Typ Max Min Typ Max Units ACCURACY TA = 0°C to +70°C TA = –25°C to +105°C OUTPUT CHARACTERISTICS Nominal Current Output @ +25°C (298.2K) 298.2 298.2 298.2 µA Temperature Coefficient 1 1 1 µA/°C Repeatability4 0.1 0.1 0.1 °C Long Term Stability5 0.1 0.1 0.1 °C/month ABSOLUTE MAXIMUM RATINGS Operating Temperature –25 +105 –25 +105 –25 +105 °C Package Temperature6 –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 NOTES 1An external calibration trim can be used to zero the error @ +25 °C. 2Defined as the maximum deviation from a mathematically best fit line. 3Parameter tested on all production units at +105 °C only. C grade at –25 °C also. 4Maximum deviation between +25 °C readings after a temperature cycle between –45 °C and +125 °C. Errors of this type are noncumulative. 5Operation @ +125 °C, error over time is noncumulative. 6Although 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. (typical @ TA = +258C, VS = +5 V, unless otherwise noted) TEMPERATURE SCALE CONVERSION EQUATIONS METALIZATION DIAGRAM 66MILS 42MILS REV. –2– °R = °F +459.7 K = °C +273.158C = 9 (8F –32) 8F = 8C +32 B
Typical Performance Curves–AD592 Typical @ VS = +5 V TOTAL ERROR – oC TEMPERATURE – oC –25 0 +25 +70 +105 +2.0 +1.5 +1.0 +0.5 –0.5 –1.0 –1.5 –2.0 AD592CN Accuracy Over Temperature +2.0 +1.5 +1.0 +0.5 –0.5 –1.0 –1.5 TEMPERATURE – oC TOTAL ERROR – oC AD592AN Accuracy Over Temperature TOTAL ERROR – oC TEMPERATURE – oC –25 0 +25 +70 +105 +2.0 +1.5 +1.0 +0.5 –0.5 –1.0 –1.5 –2.0 AD592BN Accuracy Over Temperature 0.75 0.50 0.25 –0.25 –0.50 –0.75 0 500 1000 1500 2000 TIME – Hours TOTAL ERROR – oC Long-Term Stability @ +85 °C and 85% Relative Humidity REV. –3– 0.75 0.50 0.25 –0.25 –0.50 –0.75 0 500 1000 1500 2000 TIME – Hours TOTAL ERROR – oC Long-Term Stability @ +125 °C B
to 1 can be easily achieved using the above technique. 4–20 mA transmitter for use with 40 V, 1 k Ω systems. Figure 12. Temperature to 4–20 mA Current Transmitter
8 BITS
Figure 13. Temperature to Digital Output using the AD592 in the circuit of Figure 14. Figure 14. Variable Temperature Thermostat Figure 15. Remote Temperature Multiplexing
of channels of the decoder and MUX.
- A 7-bit digital word is all that is required to select one of
sensors off for minimum dissipation while idling.
4028 BCD TO DECIMAL DECODER
Figure 16. Matrix Multiplexer justment. This step is independent of the gain selection. Figure 17. Celsius or Fahrenheit Thermometer
Rev. B | Page 9 OUTLINE DIMENSIONS 042208-A CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. COMPLIANT TO JEDEC STANDARDS TO-226-AA 0.020 (0.51) 0.017 (0.43) 0.014 (0.36) 0.1150 (2.92) 0.0975 (2.48) 0.0800 (2.03) 0.165 (4.19) 0.145 (3.68) 0.125 (3.18) BOTTOM VIEW FRONT VIEW 0.0220 (0.56) 0.0185 (0.47) 0.0150 (0.38) 0.105 (2.68) 0.100 (2.54) 0.095 (2.42) 0.055 (1.40) 0.050 (1.27) 0.045 (1.15) SEATING PLANE 0.500 (12.70) MIN 0.205 (5.21) 0.190 (4.83) 0.175 (4.45) 0.210 (5.33) 0.190 (4.83) 0.170 (4.32) Figure 18. 3-Pin Plastic Header-Style Package [TO-92]
REVISION HISTORY
6/15—Rev. A to Rev. B ©2015 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the prop erty of their respective owners. D09374-0-6/15(B)