Document
AD590
August 1997
2-Wire, Current Output Temperature Transducer
Description
The AD590 is an integrated-circuit temperature transducer which produces an output current proportional to absolute temperature. The device acts as a high impedance constant current regulator, passing 1µA/oK for supply voltages between +4V and +30V. Laser trimming of the chip's thin film resistors is used to calibrate the device to 298.2µA output at 298.2oK (25oC). The AD590 should be used in any temperature-sensing application between -55oC to 150oC 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 the simplest application, a resistor, a power source and any voltmeter can be used to measure temperature. In addition to temperature measurement, applications include temperature compensation or correction of discrete components, and biasing proportional to absolute temperature. 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 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
• Linear Current Output . . . . . . . . . . . . . . . . . . . . 1µA/oK • Wide Temperature Range . . . . . . . . . . . -55oC to 150oC • Two-Terminal Device Voltage In/Current Out • Wide Power Supply Range . . . . . . . . . . . . . +4V to +30V • Sensor Isolation From Case • Low Cost
Ordering Information
NONPART LINEARITY TEMP. RANGE NUMBER (oC) (oC) AD590IH ±3.0 ±1.5 -55 to 150 PKG. NO. T3.A
PACKAGE 3 Ld Metal Can (TO-52) 3 Ld Metal Can (TO-52)
AD590JH
-55 to 150
T3.A
Pinout
AD590 (METAL CAN)
Functional Diagram
+ R1 260Ω + Q2 Q6 C1 26pF R2 1040Ω Q5 Q3 Q4
1 3 CASE
Q1
Q7
Q12
Q8
-
2 CHIP SUBSTRATE R3 5kΩ Q10 1 R6 820Ω R5 146Ω R4 11kΩ
Q9 8
Q11 1
-
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. http://www.intersil.com or 407-727-9207 | Copyright © Intersil Corporation 1999
File Number
3171.1
12-3
AD590
Absolute Maximum Ratings
TA = 25oC
Thermal Information
Thermal Resistance (Typical, Note 1) θJA (oC/W) θJC (oC/W) Metal Can Package . . . . . . . . . . . . . . . 200 120 Maximum Junction Temperature (Metal Can Package) . . . . . . . 175oC Maximum Storage Temperature Range . . . . . . . . . .-65oC to 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300oC
Supply Forward Voltage (V+ to V-) . . . . . . . . . . . . . . . . . . . . . . +44V Supply Reverse Voltage (V+ to V-) . . . . . . . . . . . . . . . . . . . . . . .-20V Breakdown Voltage (Case to V+ to V-) . . . . . . . . . . . . . . . . . . ±200V Rated Performance Temperature Range TO-52. . . . -55oC to 150oC
Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . -55oC to 150oC
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE: 1. θJA is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
PARAMETER
Typical Values at TA = 25οC, V+ = 5V, Unless Otherwise Specified TEST CONDITIONS AD590I 298.2 1.0 Notes 1, 5 -55oC to 150oC, Note 7 ±20.0 Max ±5.8 Max Note 6 Notes 2, 6 Notes 3, 6 ±3.0 Max ±0.1 Max ±0.1 Max 40 ±10.0 Max ±3.0 Max ±1.5 Max ±0.1 Max ±0.1 Max 40
oC oC oC oC oC/Month
AD590J 298.2 1.0 ±5.0 Max
UNITS µA µA/oK
oC
Nominal Output Current at 2oC (298.2oK) Nominal Temperature Coefficient Calibration Error at 25oC Absolute Error Without External Calibration Adjustment With External Calibration Adjustment Non-Linearity Repeatability Long Term Drift Current Noise Power Supply Rejection +4V < V+ < +5V +5V < V+ < +15V +15V < V+ < +30V Case Isolation to Either Lead Effective Shunt Capacitance Electrical Turn-On Time Reverse Bias Leakage Current Power Supply Range NOTES: 2. Does not include self heating effects. Note 1 Note 4
±10.0 Max
pA/√Hz
0.5 0.2 0.1 1010 100 20 10 +4 to +30
0.5 0.2 0.1 1010 100 20 10 +4 to +30
µA/V µA/V µA/V Ω pF µs pA V
3. Maximum deviation between 25oC reading after temperature cycling between -55oC and 150oC. 4. Conditions constant +5V, constant 125oC. 5. Leakage current doubles every 10oC. 6. Mechanical strain on package may disturb calibration of dev.