Intersil Corporation AD590 Datasheet
August 1997
AD590
2-Wire, Current Output
Temperature Transducer
Features
• Linear Current Output . . . . . . . . . . . . . . . . . . . .1µA/oK
o
• Wide Temperature Range . . . . . . . . . . . -55
C to 150oC
• Two-Terminal Device Voltage In/Current Out
• Wide Power Supply Range . . . . . . . . . . . . .+4V to +30V
• Sensor Isolation From Case
• Low Cost
Ordering Information
NON-
PART
NUMBER
AD590IH ±3.0 -55 to 150 3 Ld Metal Can
AD590JH ±1.5 -55 to 150 3 Ld Metal Can
LINEARITY
(oC)
TEMP . RANGE
(oC) PACKAGE
PKG.
NO.
T3.A
(TO-52)
T3.A
(TO-52)
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/
+30V. Laser trimming of the chip's thin film resistors is used to
calibrate the device to 298.2µA output at 298.2
The AD590 should be used in any temperature-sensing
application between -55
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 man y 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 pow er 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.
o
K for supply voltages between +4V and
o
K (25oC).
o
C to 150oC in which conventional
Pinout
AD590
(METAL CAN)
+
1
CASE
3
2
-
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
Functional Diagram
Q2
Q1
SUBSTRATE
Q9
8
R6 820Ω R5 146Ω
12-3
+
R1 260Ω R2 1040Ω
Q6
Q7 Q8
CHIP
Q12
R3 5kΩ R4 11kΩ
-
Q10
Q3
Q5
1
Q4
C1 26pF
Q11
1
File Number 3171.1
AD590
Absolute Maximum Ratings T
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 Typical Values at T
PARAMETER TEST CONDITIONS AD590I AD590J UNITS
o
Nominal Output Current at 2
Nominal Temperature Coefficient 1.0 1.0 µA/oK
Calibration Error at 25oC Notes 1, 5 ±10.0 Max ±5.0 Max
Absolute Error -55oC to 150oC, Note 7
Without External Calibration Adjustment ±20.0 Max ±10.0 Max
With External Calibration Adjustment ±5.8 Max ±3.0 Max
Non-Linearity Note 6 ±3.0 Max ±1.5 Max
Repeatability Notes 2, 6 ±0.1 Max ±0.1 Max
Long Term Drift Notes 3, 6 ±0.1 Max ±0.1 Max
C (298.2oK) 298.2 298.2 µA
= 25oC Thermal Information
A
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
= 25οC, V+ = 5V, Unless Otherwise Specified
A
o
C
o
C
o
C
o
C
o
C
o
C/Month
Current Noise 40 40 pA/√Hz
Power Supply Rejection
+4V < V+ < +5V 0.5 0.5 µA/V
+5V < V+ < +15V 0.2 0.2 µA/V
+15V < V+ < +30V 0.1 0.1 µA/V
Case Isolation to Either Lead 10
Effective Shunt Capacitance 100 100 pF
Electrical Turn-On Time Note 1 20 20 µs
Reverse Bias Leakage Current Note 4 10 10 pA
Power Supply Range +4 to +30 +4 to +30 V
NOTES:
2. Does not include self heating effects.
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 device.
7. Guaranteed but not tested.
8. -55oC Guaranteed by testing at 25oC and 150oC.
10
10
10
Ω
12-4
AD590
Trimming Out Errors
The ideal graph of current versus temperature for the AD590
is a straight line, but as Figure 1 shows, the actual shape is
slightly different. Since the sensor is limited to the range of
o
-55
C to 150oC, it is possible to optimize the accuracy by
trimming. Trimming also permits extracting maximum
performance from the lower-cost sensors.
The circuit of Figure 2 trims the slope of the AD590 output.
The effect of this is shown in Figure 3.
The circuit of Figure 4 trims both the slope and the offset.
This is shown in Figure 5. The diagrams are exaggerated to
show effects, but it should be clear that these trims can be
used to minimize errors over the whole range, or over any
selected part of the range. In fact, it is possible to adjust the
I-grade device to give less than 0.1
o
0
C to 90oC and less than 0.05oC error from 25oC to 60oC.
I (µA)
o
C error over the range
IDEAL
ACTUAL
(GREATLY
EXAGGERATED)
+10V
35.7kΩ
R1 2kΩ
AD590
97.6kΩ R
+
5kΩ
2
V
OUT
= 100mV/oC
-
V-
FIGURE 4. SLOPE AND OFFSET TRIMMING
R1 = OFFSET
= SLOPE
R
2
FIGURE 5A. UNTRIMMED
T (oK)
FIGURE 1. TRIMMING OUT ERRORS
+5V
+
+
AD590
-
+
R 100Ω
V
= 1mV/oK
950Ω
FIGURE 2. SLOPE TRIMMING
I (µA)
OUT
R = SLOPE
IDEAL
FIGURE 5B. TRIM ONE: OFFSET
ACTUAL
TRIMMED
T (oK)
FIGURE 3. EFFECT OF SLOPE TRIM
FIGURE 5C. TRIM TWO: SLOPE
12-5
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