ANALOG DEVICES AD 590 JH Datasheet

2-Terminal IC

2

–

Data Sheet

FEATURES

Linear current output: 1 μA/K
Wide temperature range: −55°C to +150°C
Probe-compatible ceramic sensor package
2-terminal device: voltage in/current out
Laser trimmed to ±0.5°C calibration accuracy (AD590M)
Excellent linearity: ±0.3°C over full range (AD590M)
Wide power supply range: 4 V to 30 V
Sensor isolation from case
Available in 2-lead FLATPACK, 4-lead LFCSP, 3-pin TO-52,

8-lead SOIC, and die form

GENERAL DESCRIPTION

The AD590 is a 2-terminal integrated circuit temperature trans­ducer that produces an output current proportional to absolute
temperature. For supply voltages between 4 V and 30 V, the device
acts as a high impedance, constant current regulator passing
1 μA/K. Laser trimming of the chip’s thin-film resistors is used
to calibrate the device to 298.2 μA output at 298.2 K (25°C).

The AD590 should be used in any temperature-sensing
application below 150°C 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 addition to temperature measurement, applications include
temperature compensation or correction of discrete components,
biasing proportional to absolute temperature, flow rate measure­ment, level detection of fluids and anemometry. The AD590 is
available in die form, making it suitable for hybrid circuits and
fast temperature measurements in protected environments.

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 at 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.

Temperature Transducer

AD590

PIN CONFIGURATIONS

1V+

AD590

TOP VIEW

(Not to Scale)

PIN 5 (EXPOSED PAD)

2V–

NOTES

1. NC = NO CONNECT. THE NC PIN IS NOT
BONDED TO THE DIE I NT E RNALLY.

. TO ENSURE CORRECT OPERATION, THE

EXPOSEDPAD (EP) SHOULD BE LEFT FLOATING.

+–

Figure 1. 2-Lead

FLATPACK

00533-024

Figure 2. 4-Lead LFCSP

NC

1
2

V+

TOP VIEW

(Not to Scale)

V–

+

Figure 3. 3-Pin TO-52

0533-025

3
4

NC

NC = NO CONNECT

Figure 4. 8-Lead SOIC

PRODUCT HIGHLIGHTS

1. The AD590 is a calibrated, 2-terminal temperature sensor

requiring only a dc voltage supply (4 V to 30 V). Costly
transmitters, filters, lead wire compensation, and lineari­zation circuits are all unnecessary in applying the device.

2. State-of-the-art laser trimming at the wafer level in

conjunction with extensive final testing ensures that
AD590 units are easily interchangeable.

3. Superior interface rejection occurs because the output is a

current rather than a voltage. In addition, power
requirements are low (1.5 mW @ 5 V @ 25°C). These
features make the AD590 easy to apply as a remote sensor.

4. The high output impedance (>10 MΩ) provides excellent

rejection of supply voltage drift. For instance, changing the
power supply from 5 V to 10 V results in only a 1 μA
maximum current change, or 1°C equivalent error.

5. The AD590 is electrically durable: it withstands a forward

voltage of up to 44 V and a reverse voltage of 20 V.
Therefore, supply irregularities or pin reversal does not
damage the device.

4NC

3NC

NC

8
7

NC
NC

6
5

NC

00533-001

00533-104

Rev. G Document Feedback

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Technical Support www.analog.com

AD590 Data Sheet

TABLE OF CONTENTS

Features .....................................................................................1

General Description ..................................................................1

Pin Configurations ....................................................................1

Product Highlights ....................................................................1

Revision History ........................................................................2

Specifications .............................................................................3

AD590J and AD590K Specifications ......................................3

AD590L and AD590M Specifications ....................................4

Absolute Maximum Ratings ......................................................5

ESD Caution ..........................................................................5

Product Description ..................................................................6

REVISION HISTORY

1/13—R e v. F to Rev. G

Changes to Endnote 2, Table 1 ...................................................3

Changes to Ordering Guide .....................................................15

11/12—Rev. E to Rev. F

Added 4-Lead L FCSP_W D ......................................... Univers al

Changes to Features Section, General Description Se ction, and

Product Highlights Section........................................................1

Added Figure 2; Renumbered Sequentially................................1

Added Note 2, Table 1 ; Renumbered Sequentially .....................3

Changes to (Unbolded) For 8-Lead SOIC Package, AD590J and

AD590K Parameter, Table 1.......................................................3

Changes to Note 1, Tabl e 3.........................................................5

Changes to Product Description Section ...................................6

Change to Figure 6.....................................................................6

Changes to Explanation of Temperature Sensor Specifications

Section .......................................................................................7

Moved Nonlinearity Section ......................................................8

Change to Figure 13...................................................................8

Changes to General Applications Se ction ................................10

Changes to Figure 17 and Figure 19.........................................10

Explanation of Temperature Sensor Specifications ................ 7

Calibration Error ................................................................... 7

Error vs. Temperature: Calibration Error Trimmed Out........ 7

Error vs. Temperature: No User Trims ................................... 7

Nonlinearity .......................................................................... 8

Voltage and Thermal Environment Effects ............................ 8

General Applications ............................................................... 10

Outline Dimensions ................................................................ 13

Ordering Guide ................................................................... 15

Deleted Figure 22; Renumbered Sequentially .......................... 11

Changes to Figure 2 1 and Figure 22 ........................................ 11

Deleted Figure 24 .................................................................... 12

Changes to Figure 24 ............................................................... 12

Updated Outline Dimensions Section ..................................... 14

Changes to Ordering Guide..................................................... 14

9/09—R e v. D to R ev. E

Changes to Product Description Section ................................... 6

Updated Outline Dimensions .................................................. 13

Changes to Ordering Guide..................................................... 14

1/06—R ev. C t o R ev. D

Updated Format ...........................................................Universal

Changes to Figure 4 E q uation.................................................... 4

9/03—R ev. B t o R ev. C

Added SOIC-8 Package ................................................Universal

Change to Figure 1 .................................................................... 1

Updated Outline Dimensions .................................................. 13

Added Ordering Guide............................................................ 14

Rev. G | Page 2 of 16

Data Sheet AD590

AD590J2

AD590K

Parameter

Min

Typ

Max

Min

Typ

Max

Unit

OUTPUT

Nominal Temperature Coefficient

1 1 µA/K

±5.0

±2.5

Without External Calibration Adjustment

±10

±5.5

°C

With 25°C C alibrati on Error Set to Zero

±3.0

±2.0

°C

For 8-Lead SOIC Package

±1.5

±1.0

°C

For 4-Lead LFCSP Package

±1.5 °C

Repeatability3

±0.1

±0.1

°C

Current Noise

40

40 pA/√Hz

15 V ≤ VS ≤ 30 V

0.1

0.1 µA/V

Case Isolation to Either Lead

1010

1010 Ω

Effective Shunt Capacitance

100

100 pF

Electrical Turn-On Time

20

20 µs

SPECIFICATIONS

AD590J AND AD590K SPECIFICATIONS

25°C and VS = 5 V, unless otherwise noted.1

Table 1.

POWER SUPPLY

Ope rati ng Volt age Range 4 30 4 30 V

Nominal Current Output @ 25°C (298.2 K) 298.2 298.2 µA

Calibration Error @ 25°C
Absolute Error (Over Rated Performance Temperature Range)

°C

Nonlinearity

For TO-52 and FLATPACK Packages ±1.5 ±0.8 °C

Long-Term Drift4 ±0.1 ±0.1 °C

Power Supply Rejection

4 V ≤ VS ≤ 5 V 0.5 0.5 µA/V
5 V ≤ VS ≤ 15 V 0.2 0.2 µV/V

Reverse Bias Leakage Current (Reverse Voltage = 10 V)5 10 10 pA

1

Specif ications shown in b oldface are tes ted on all production uni ts at fi nal ele ctrical te st. Re sults from those tests are used to c alculate o utgoing quality le vels. All

minimum and maximum specifications are guaranteed, al though only those shown in boldface are tested on all production u nits.

2

The LFC SP package has a reduced operating temperature range of −40°C to +125°C.

3

Maximum deviation be tween +25°C readings after te mperature cycling betw een −55°C and +150°C; guarante ed, no t tested.

4

Conditio ns: constant 5 V, c onstant 125°C; guarantee d, not teste d.

5

Leakage current doubles every 10°C.

Rev. G | Page 3 of 16

AD590 Data Sheet





AD590L AND AD590M SPECIFICATIONS

25°C and VS = 5 V, unless otherwise noted.1

Table 2.

AD590L AD590M
Parameter Min Typ Max Min Typ Max Unit

POWER SUPPLY

Operating Voltage Range

OUTPUT

Nominal Current Output @ 25°C (298.2 K) 298.2 298.2 μA
Nominal Temperature Coefficient 1 1 μA/K
Calibration Error @ 25°C
Absolute Error (Over Rated Performance Temperature Range) °C

Without External Calibration Adjustment
With ± 25°C Calibration Error Set to Zero
Nonlinearity
Repeatability2 ±0.1 ±0.1 °C

Long-Term Drift3 ±0.1 ±0.1 °C
Current Noise 40 40 pA/√Hz
Power Supply Rejection

4 V ≤ VS ≤ 5 V 0.5 0.5 μA/V

5 V ≤ VS ≤ 15 V 0.2 0.2 μA/V

15 V ≤ VS ≤ 30 V 0.1 0.1 μA/V
Case Isolation to Either Lead 1010 1010 Ω
Effective Shunt Capacitance 100 100 pF
Electrical Turn-On Time 20 20 μs
Reverse Bias Leakage Current (Reverse Voltage = 10 V)4 10 10 pA

1

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

minimum and maximum specifications are guaranteed, although only those shown in boldface are tested on all production units.

2

Maximum deviation between +25°C readings after temperature cycling between −55°C and +150°C; guaranteed, not tested.

3

Conditions: constant 5 V, constant 125°C; guaranteed, not tested.

4

Leakage current doubles every 10°C.

+223°

°K
°C

–50°

+273°0°+298°

+25°

+323°

+50°

30 4 30 V

4

±0.5

±1.7
±1.0
±0.3

+373°
+100°

±1.0

±3.0
±1.6
±0.4

+423°
+150°

°C

°C
°C
°C

–100° 0° +100° +200° +300°

°F

Figure 5. Temperature Scale Conversion Equations

+32° +70° +212°

5
9

9



 FRCF



5





 CKFC










00533-002

15.27332

7.45932

Rev. G | Page 4 of 16

Data Sheet AD590

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Forward Voltage ( E+ or E−) 44 V

Reverse Voltage (E+ to E−) −20 V

Breakdown Voltage (Case E+ or E−) ±200 V

Rated Performance Temperature Range1 −55°C to +150°C

Storage Temperature Range1 −65°C to +155°C

Lead Temperature (Soldering, 10 sec) 300°C

1

The AD590 was used at −100°C and +200°C for short periods of

measurement with no physical damage to the device. However, the absolute
errors specified apply to only the rated performance temperature range.
Applicable to 2-lead FLATPACK and 3-pin TO-52 packages only.

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only and functional operation of the device at these or
any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

ESD CAUTION

Rev. G | Page 5 of 16

AD590 Data Sheet

(

PRODUCT DESCRIPTION

The AD590 is a 2-terminal temperature-to-voltage transducer. It
is available in a variety of accuracy grades and packages. When
using the AD590 in die form, the chip substrate must be kept
electrically isolated (floating) for correct circuit operation.

1725µM

V–

1090µM

Figure 8 shows the typical V–I characteristic of the circuit at
25°C and the temperature extremes.

+

R2

R1

1040Ω

260Ω

Q2

Q6

Q5 Q3

Q12

C1

26pF

Q8

Q4

Q1

Q7

V+

Figure 6. Metallization Diagram

00533-003

The AD590 uses a fundamental property of the silicon
transistors from which it is made to realize its temperature
proportional characteristic: if two identical transistors are
operated at a constant ratio of collector current densities, r,
then the difference in their base-emitter voltage is (kT/q)(In r).
Because both k (Boltzman’s constant) and q (the charge of an
electron) are constant, the resulting voltage is directly pro­portional to absolute temperature (PTAT). (For a more detailed
description, see M.P. Timko, “A Two-Terminal IC Temperature
Transducer,” IEEE J. Solid State Circuits, Vol. SC-11, p. 784-788,
Dec. 1976. Understanding the Specifications–AD590.)

In the AD590, this PTAT voltage is converted to a PTAT current
by low temperature coefficient thin-film resistors. The total
current of the device is then forced to be a multiple of this
PTAT current. Figure 7 is the schematic diagram of the AD590.
In this figure, Q8 and Q11 are the transistors that produce the
PTAT voltage. R5 and R6 convert the voltage to current. Q10,
whose collector current tracks the collector currents in Q9 and
Q11, supplies all the bias and substrate leakage current for the
rest of the circuit, forcing the total current to be PTAT. R5 and
R6 are laser-trimmed on the wafer to calibrate the device at 25°C.

R5

146Ω

R3
5kΩ

R4
11kΩ

Q10Q9

Q11

118

00533-004

CHIP

SUBSTRATE

R6
820Ω

–

Figure 7. Schematic Diagram

423

298

µA)

OUT

I

218

012

34

SUPPLY VOLTAGE (V)

Figure 8. V–I Plot

+150°C

+25°C

–55°C

56 30

00533-005

Rev. G | Page 6 of 16

Data Sheet AD590

(

V

EXPLANATION OF TEMPERATURE SENSOR

SPECIFICATIONS

The way in which the AD590 is specified makes it easy to apply

it in a wide variety of applications. It is important to understand

the meaning of the various specifications and the effects of the

supply voltage and thermal environment on accuracy.

The AD590 is a PTAT current regulator. (Note that T (°C) =

T (K) − 273.2. Zero on the Kelvin scale is absolute zero; there is

no lower temperature.) That is, the output current is equal to a

scale factor times the temperature of the sensor in degrees

Kelvin. This scale factor is trimmed to 1 μA/K at the factory, by

adjusting the indicated temperature (that is, the output current)

to agree with the actual temperature. This is done with 5 V

across the device at a temperature within a few degrees of 25°C

(298.2 K). The device is then packaged and tested for accuracy

over temperature.

CALIBRATION ERROR

At final factory test, the difference between the indicated

temperature and the actual temperature is called the calibration

error. Since this is a scale factory error, its contribution to the

total error of the device is PTAT. For example, the effect of the

1°C specified maximum error of the AD590L varies from 0.73°C

at −55°C to 1.42°C at 150°C. Figure 9 shows how an exaggerated

calibration error would vary from the ideal over temperature.

ACTUAL

TRANSFER

FUNCTION

temperature range. In most applications, there is a current-to­voltage conversion resistor (or, as with a current input ADC, a
reference) that can be trimmed for scale factor adjustment.

+

5

–

100Ω

950Ω

R

+

AD590

–

V

= 1mV/K

T

+

00533-007

–

Figure 10. One Temperature Trim

ERROR VS. TEMPERATURE: CALIBRATION ERROR TRIMMED OUT

Each AD590 is tested for error over the temperature range with
the calibration error trimmed out. This specification could also
be called the variance from PTAT, because it is the maximum
difference between the actual current over temperature and a
PTAT multiplication of the actual current at 25°C. This error
consists of a slope error and some curvature, mostly at the
temperature extremes. Figure 11 shows a typical AD590K
temperature curve before and after calibration error trimming.

2

0

BEFORE
CALIBRATION
TRIM

CALIBR ATION

ERROR

I

ACTUAL

µA)

OUT

I

298.2

CALIBRATION
ERROR

298.2

TEMPERATURE (°K)

IDEAL

TRANSFER

FUNCTION

00533-006

Figure 9. Calibration Error vs. Temperature

The calibration error is a primary contributor to the maximum

total error in all AD590 grades. However, because it is a scale

factor error, it is particularly easy to trim. Figure 10 shows the

most elementary way of accomplishing this.

To trim this circuit, the temperature of the AD590 is measured

by a reference temperature sensor and R is trimmed so that V

T

= 1 mV/K at that temperature. Note that when this error is

trimmed out at one temperature, its effect is zero over the entire

ABSOLUTE E RROR (°C)

–2

–55 150

AFTER
CALIBRATION
TRIM

TEMPERATURE (°C)

00533-008

Figure 11. Effect to Scale Factor Trim on Accuracy

ERROR VS. TEMPERATURE: NO USER TRIMS

Using the AD590 by simply measuring the current, the total
error is the variance from PTAT, described above, plus the effect
of the calibration error over temperature. For example, the
AD590L maximum total error varies from 2.33°C at −55°C to

3.02°C at 150°C. For simplicity, only the large figure is shown
on the specification page.

Rev. G | Page 7 of 16

AD590 Data Sheet

V

R

A

NONLINEARITY

Nonlinearity as it applies to the AD590 is the maximum
deviation of current over temperature from a best-fit straight
line. The nonlinearity of the AD590 over the −55°C to +150°C
range is superior to all conventional electrical temperature
sensors such as thermocouples, RTDs, and thermistors. Figure 12
shows the nonlinearity of the typical AD590K from Figure 11.

1.6

2

TURE (°C)

0

TEMPE

0.8

0.8°C MAX

0

0.8°C
MAX

ABSOLUTE ERROR (°C)

–0.8

–1.6

–55 150

TEMPERATURE (°C)

0.8°C
MAX

00533-009

Figure 12. Nonlinearity

Figure 13 shows a circuit in which the nonlinearity is the major
contributor to error over temperature. The circuit is trimmed
by adjusting R1 for a 0 V output with the AD590 at 0°C. R2 is
then adjusted for 10 V output with the sensor at 100°C. Other
pairs of temperatures can be used with this procedure as long as
they are measured accurately by a reference sensor. Note that
for 15 V output (150°C), the V+ of the op amp must be greater
than 17 V. Also, note that V− should be at least −4 V; if V− is
ground, there is no voltage applied across the device.

15

AD581

35.7kΩ

27kΩ

R1

2kΩ

97.6kΩ

R2

5kΩ

30pF

OP177

100mV/°C
V

= 100mV/°C

T

AD590

V–

00533-010

Figure 13. 2-Temperature Trim

–2

–55 0 150100

TEMPERATURE (°C)

00533-011

Figure 14. Typical 2-Trim Accuracy

VOLTAGE AND THERMAL ENVIRONMENT EFFECTS

The power supply rejection specifications show the maximum
expected change in output current vs. input voltage changes.
The insensitivity of the output to input voltage allows the use of
unregulated supplies. It also means that hundreds of ohms of
resistance (such as a CMOS multiplexer) can be tolerated in
series with the device.

It is important to note that using a supply voltage other than 5 V
does not change the PTAT nature of the AD590. In other words,
this change is equivalent to a calibration error and can be
removed by the scale factor trim (see Figure 11).

The AD590 specifications are guaranteed for use in a low
thermal resistance environment with 5 V across the sensor.
Large changes in the thermal resistance of the sensor’s environment
change the amount of self-heating and result in changes in the
output, which are predictable but not necessarily desirable.

The thermal environment in which the AD590 is used
determines two important characteristics: the effect of self­heating and the response of the sensor with time. Figure 15 is a
model of the AD590 that demonstrates these characteristics.

T

θ

T

JC

J

P

C

CH

Figure 15. Thermal Circuit Model

θ

CA

C

+

T

C

C

A

–

00533-012

Rev. G | Page 8 of 16

Data Sheet AD590

As an example, for the TO-52 package, θJC is the thermal
resistance between the chip and the case, about 26°C/W. θ

is

CA

the thermal resistance between the case and the surroundings
and is determined by the characteristics of the thermal
connection. Power source P represents the power dissipated
on the chip. The rise of the junction temperature, T
ambient temperature, T

− TA = P(θJC + θCA) (1)

T

J

Tabl e 4 g i ves the s u m o f θ

, is

A

and θCA for several common

JC

, above the

J

thermal media for both the H and F packages. The heat sink
used was a common clip-on. Using Equation 1, the temperature
rise of an AD590 H package in a stirred bath at 25°C, when
driven with a 5 V supply, is 0.06°C. However, for the same
conditions in still air, the temperature rise is 0.72°C. For a given
supply voltage, the temperature rise varies with the current and
is PTAT. Therefore, if an application circuit is trimmed with the
sensor in the same thermal environment in which it is used, the
scale factor trim compensates for this effect over the entire
temperature range.

Table 4. Thermal Resistance

θ

+ θCA

JC

(°C/Watt) τ (sec)

1

Medium H F H F

Aluminum Block 30 10 0.6 0.1
Stirred Oil2 42 60 1.4 0.6
Moving Air3

With Heat Sink 45 – 5.0 –
Without Heat Sink 115 190 13.5 10.0

Still Air

With Heat Sink 191 – 108 –
Without Heat Sink 480 650 60 30

1

τ is dependent upon velocity of oil; average of several velocities listed above.

2

Air velocity @ 9 ft/sec.

3

The time constant is defined as the time required to reach 63.2% of an

instantaneous temperature change.

The time response of the AD590 to a step change in
temperature is determined by the thermal resistances and the
thermal capacities of the chip, C
about 0.04 Ws/°C for the AD590. C

, and the case, CC. CCH is

CH

varies with the measured

C

medium, because it includes anything that is in direct thermal
contact with the case. The single time constant exponential
curve of Figure 16 is usually sufficient to describe the time
response, T (t). Table 4 shows the effective time constant, τ, for
several media.

T

FINAL

) × (1 – e

–t/

)

00533-013

T

INITIAL

+ (T

T(t) = T

INITIAL

SENSED TEMPERATURE

 4

Figure 16. Time Response Curve

FINAL

TIME

– T

INITIAL

Rev. G | Page 9 of 16

AD590 Data Sheet

AD590

I

T

I

T

I

T

+

–

00533-014

7V

1k

0.1% LOW
TCR RESISTOR
1mV/k

00533-015

AD590

+

–

AD590

+

–

AD590

+

–

+

VT MIN

10kΩ

(0.1%)

–

+

–

AD590

+

–

+

–

+

VTAVG

333.3Ω
(0.1%)

–

5V

15V

00533-016

AD590L

#2

+

–

AD590

L

#1

+

–

R4

10kΩ

R3

10kΩ

R1
5MΩ

R2

50kΩ

V+

(T1 – T2) × (10mV/°C)

V–

OP177

–

+

00533-017

+

–

REFERENCE
JUNCTION

IRON

+
–

7.5V

AD590

AD580

CONS

TAN

TAN

MEASURING

JUNCTION

RESIS

T

ORS ARE 1%, 50ppm/ °C

METER

+

–

–

+

C

U

52.3Ω

8.66k

Ω

V

OUT

R

T

1k

Ω

GENERAL APPLICATIONS

Figure 17 shows a typical use of the AD590 in a remote
temperature sensing application. The AD590 is used as a
thermometer circuit that measures temperature from −55°C to
+150°C, with an output voltage of 1 mV/°K. Because the
AD590 measures absolute temperature (its nominal output is
1 mA/K), the output must be offset by 273.2 mA to read out in
degrees Celsius.

Figure 17. Variable Scale Display

Connecting several AD590 units in series, as shown in Figure 18,
allows the minimum of all the sensed temperatures to be
indicated. In contrast, using the sensors in parallel yields the

average of the sensed temperatures.

Figure 19. Differential Measurements

Figure 20 is an example of a cold junction compensation circuit
for a Type J thermocouple using the AD590 to monitor the
reference junction temperature. This circuit replaces an ice-bath
as the thermocouple reference for ambient temperatures
between 15°C and 35°C. The circuit is calibrated by adjusting R

T

for a proper meter reading with the measuring junction at a
known reference temperature and the circuit near 25°C. Using
components with the TCs as specified in Figure 20, compensation
accuracy is within ±0.5°C for circuit temperatures between 15°C
and 35°C. Other thermocouple types can be accommodated with
different resistor values. Note that the TCs of the voltage
reference and the resistors are the primary contributors to error.

Figure 18. Series and Parallel Connection

The circuit in Figure 19 demonstrates one method by which
differential temperature measurements can be made. R1 and R2
can be used to trim the output of the op amp to indicate a
desired temperature difference. For example, the inherent offset
between the two devices can be trimmed in. If V+ and V− are
radically different, then the difference in internal dissipation
causes a differential internal temperature rise. This effect can be
used to measure the ambient thermal resistance seen by the
sensors in applications such as fluid-level detectors or anemometry.

Figure 20. Cold Junction Compensation Circuit for Type J Thermocouple

Rev. G | Page 10 of 16

Data Sheet AD590

00533-018

30pF

V+

4mA = 17°C
12mA = 25°C
20mA = 33°C

–

+

–

+

AD581

V

OUT

R

T

5kΩ

10Ω

10kΩ

12.7kΩ

35.7kΩ

5kΩ 500Ω

AD590

OP177

–

+

0.01µF

V–

00533-019

AD790

–

+

C1

2

3

4

1

7

10kΩ

R

SET

R

L

R

B

R

H

V–

V+

V+

AD590

–

+

AD581

OUT

HEATING
ELEMENTS

GND

10V

00533-021

5V

CMOS
GATES

AD590

1kΩ (0.1%)

–

+

–

+

–

+

–

+

Figure 21 is an example of a current transmitter designed to be
used with 40 V, 1 kΩ systems; it uses its full current range of 4
to 20 mA for a narrow span of measured temperatures. In this
example, the 1 µA/K output of the AD590 is amplified to
1 mA/°C and offset so that 4 mA is equivalent to 17°C and
20 mA is equivalent to 33°C. R
at an intermediate reference temperature. With a suitable choice
of resistors, any temperature range within the operating limits

of the AD590 can be chosen.

Figure 21. 4 to 20 mA Current Transmitter

Figure 22 is an example of a variable temperature control circuit
(thermostat) using the AD590. RH and RL are selected to set the
high and low limits for R
calibrated multiturn pot, or a switched resistive divider. Powering
the AD590 from the 10 V reference isolates the AD590 from
supply variations while maintaining a reasonable voltage (~7 V)
across it. Capacitor C1 is often needed to filter extraneous noise
from remote sensors. R

B

transistor and the current requirements of the load.

is trimmed for proper reading

T

. R

could be a simple pot, a

SET

SET

is determined by the β of the power

Figure 22. Simple Temperature Control Circuit

The voltage compliance and the reverse blocking characteristic
of the AD590 allow it to be powered directly from 5 V CMOS
logic. This permits easy multiplexing, switching, or pulsing for
minimum internal heat dissipation. In Figure 23, any AD590
connected to a logic high passes a signal current through the
current measuring circuitry, while those connected to a logic
zero pass insignificant current. The outputs used to drive the
AD590s can be employed for other purposes, but the additional
capacitance due to the AD590 should be taken into account.

Figure 23. AD590 Drive n f rom CMOS Logic

Rev. G | Page 11 of 16

AD590 Data Sheet

Figure 24 demonstrates a method of multiplexing the AD590 in
the 2-trim mode (see Figure 13 and Figure 14). Additional
AD590s and their associated resistors can be added to multiplex
up to eight channels of ±0.5°C absolute accuracy over the

2kΩ

35.7kΩ

+15V

AD581

+

–

V

OUT

35.7kΩ

2kΩ

5kΩ

5kΩ

temperature range of −55°C to +125°C. The high temperature
restriction of 125°C is due to the output range of the op amps;
output to 150°C can be achieved by using a 20 V supply for the
op amp.

97.6kΩ

97.6kΩ

V+

AD590L

+

–

–5V TO –15V

S1

S2

S8

+15V

–15V

+

AD590L

–

DECODER/

AD7501

TTL/DTL TO CMOS

INTERFACE

EN

DRIVER

BINARY

CHANNEL

SELECT

27kΩ

OP177

–15V

10mV/°C

00533-023

Figure 24. 8-Channel Multiplexer

Rev. G | Page 12 of 16

Data Sheet AD590

OUTLINE DIMENSIONS

0.030 (0.76)

0.500 (12.69)
MIN

0.0065 (0.17)

0.0050 (0.13)

0.0045 (0.12)

TYP

0.019 (0.48)

0.017 (0.43)

0.015 (0.38)

0.055 (1.40)

0.050 (1.27)

0.045 (1.14)

Figure 25. 2-Lead Ceramic Flat Package [FLATPACK]

Dimensions shown in inches and (millimeters)

0.150 (3.81)

0.115 (2.92)

0.195 (4.95)

0.178 (4.52)

0.230 (5.84)

0.209 (5.31)

0.030 (0.76) MAX

CONTROLLING DIM E NSIONS ARE IN INCHES; MILLIME TER DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF I NCH EQUIVALENTS F OR
REFERENCE ON LY AND ARE NOT APPROPRIATE FOR US E I N DES IGN.

0.500 (12.70)

0.050 (1.27) M AX

0.019 (0.48)

0.016 (0.41)

0.021 (0.53) MAX
BASE & SEATING PLANE

Figure 26. 3-Pin Metal Header Package [TO-52]

Dimensions shown in inches and (millimeters)

MIN

0.250 (6.35) MI N

POSITIVE LEAD
INDICATOR

0.240 (6.10)

0.230 (5.84)

0.220 (5.59)

(F-2)

0.100

(2.54)

T.P.

0.050
(1.27)

T.P.

(H-03-1)

0.210 (5.34)

0.200 (5.08)

0.190 (4.83)

0.050 (1.27) T.P.

3

2

1

45° T.P.

0.093 (2.36)

0.081 (2.06)

0.015 (0.38)
TYP

0.048 (1.22)

0.028 (0.71)

0.046 (1.17)

0.036 (0.91)

0.050 (1.27)

0.041 (1.04)

022306-A

Rev. G | Page 13 of 16

AD590 Data Sheet

4.00 (0.1574)

3.80 (0.1497)

0.25 (0.0098)

0.10 (0.0040)

COPLANARITY

0.10

CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES)ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLYAND ARE NOT APPROPRIATE FOR USE IN DESIGN.

5.00(0.1968)

4.80(0.1890)

85

1

1.27 (0.0500)

SEATING

PLANE

COMPLIANT TO JEDEC STANDARDS MS-012-AA

BSC

6.20 (0.2441)

5.80 (0.2284)

4

1.75 (0.0688)

1.35 (0.0532)

0.51 (0.0201)

0.31 (0.0122)

0.25 (0.0098)

0.17 (0.0067)

0.50 (0.0196)

0.25 (0.0099)

8°
0°

1.27 (0.0500)

0.40 (0.0157)

45°

012407-A

Figure 27. 8-Lead Standard Small Outline Package [SOIC_N]

Narrow Body

(R-8)

Dimensions shown in millimeters and (inches)

1.65

2.10

2.00

1.90

1.55

1.45

0.80 REF

413

0.20 MIN

PIN 1 INDEX

AREA

0.80

0.75

0.70

SEATING

PLANE

3.10

3.00

2.90

TOP VIEW

0.203 REF

0.35

0.30

0.25

COMPLIANTTOJEDEC STANDARDS M O-229

COPLANARITY

0.08

0.05 MAX

0.00 MIN

0.50

0.40

0.30

EXPOSED

PAD

2

BOTTOM VIEW

FOR PROP ER CONNECTI ON OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATIONS
SECTION OF THIS DATA SHEET.

1.80

1.70

1.60

1

P

N

I

A

N

D

C

I

I

5

1

.

0

R

(

Figure 28. 4-Lead Lead Frame Chip Scale Package [LFCSP_WD]

2.00 mm × 3.00 mm Body, Very Very Thin, Dual Lead
(CP-4-1)

Dimensions shown in millimeters

R

O

T
)

09-07-2010-B

Rev. G | Page 14 of 16

Data Sheet AD590

AD590JF

−55°C to +150°C

2-Le ad FLATPACK

F-2 AD590JH

−55°C to +150°C

3-P in TO-52

H-03-1

AD590KR

−55°C to +150°C

8-Le ad SOIC_N

R-8 AD590KR-REEL

−55°C to +150°C

8-Le ad SOIC_N

R-8 AD590KRZ

−55°C to +150°C

8-Le ad SOIC_N

R-8

AD590KRZ-RL

−55°C to +150°C

8-Le ad SOIC_N

R-8

AD590MH

−55°C to +150°C

3-P in TO-52

H-03-1

AD590JCHIPS

−55°C to +150°C

Bare Die

H-03-1

AD590JCPZ-R5

−40°C to +125°C

4-Lead LFCSP_WD

CP-4-1

7A

ORDERING GUIDE

1, 2

Model

AD590JR −55°C to +150°C 8-Le ad SOIC_N R-8
AD590JRZ −55°C to +150°C 8-Lead SOIC_N R-8
AD590KF −55°C to +150°C 2-Lead FLATPAC K F-2
AD590KH −55°C to +150°C 3-P in TO-52 H-03-1

AD590LF −55°C to +150°C 2-Lead FL ATPAC K F-2
AD590LH −55°C to +150°C 3-Pi n TO-52 H-03-1
AD590MF −55°C to +150°C 2-Lead FLATPA CK F-2

AD590JCPZ-RL7 −40°C to +125°C 4-Lead LFCSP_WD CP-4-1 7A

1

Z = R oHS Com pliant Part.

2

The AD590xF models and the AD590xH models are available in 883B.

Temper ature Range Package Descript ion Package Option Branding

Rev. G | Page 15 of 16

AD590 Data Sheet

NOTES

©2013 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D00533-0-1/13(G)

Rev. G | Page 16 of 16