Datasheet ADR525, ADR530, ADR550 Datasheet (ANALOG DEVICES)

High Precision Shunt Mode

V

FEATURES

Ultracompact SC70 and SOT-23-3 packages
Temperature coefficient: 40 ppm/°C (maximum)
2× the temperature coefficient improvement over the

LM4040
Pin compatible with the LM4040/LM4050
Initial accuracy: ±0.2%
Low output voltage noise: 18 μV p-p @ 2.5 V output
No external capacitor required
Operating current range: 50 μA to 15 mA
Industrial temperature range: −40°C to +85°C

APPLICATIONS

Portable, battery-powered equipment
Automotive
Power supplies
Data acquisition systems
Instrumentation and process control
Energy measurement

Table 1. Selection Guide

Temperature

Initial

Part Voltage (V)

ADR525A 2.5 ±0.4 70
ADR525B 2.5 ±0.2 40
ADR530A 3.0 ±0.4 70
ADR530B 3.0 ±0.2 40
ADR550A 5.0 ±0.4 70
ADR550B 5.0 ±0.2 40

Accuracy (%)

Coefficient
(ppm/°C)

Voltage References

ADR525/ADR530/ADR550

PIN CONFIGURATION

ADR525/

1

+

ADR530/

ADR550

2

V–

Figure 1. 3-Lead SC70 (KS) and 3-Lead SOT-23-3 (RT)

GENERAL DESCRIPTION

Designed for space-critical applications, the ADR525/ADR530/
ADR550 are high precision shunt voltage references, housed in
ultrasmall SC70 and SOT-23-3 packages. These references feature
low temperature drift of 40 ppm/°C, an initial accuracy of better
than ±0.2%, and ultralow output noise of 18 μV p-p.

Available in output voltages of 2.5 V, 3.0 V, and 5.0 V, the
advanced design of the ADR525/ADR530/ADR550 eliminates
the need for compensation by an external capacitor, yet the
references are stable with any capacitive load. The minimum
operating current increases from a mere 50 μA to a maximum
of 15 mA. This low operating current and ease of use make
these references ideally suited for handheld, battery-powered
applications.

A trim terminal is available on the ADR525/ADR530/ADR550
to allow adjustment of the output voltage over a ±0.5% range,
without affecting the temperature coefficient of the device. This
feature provides users with the flexibility to trim out small
system errors.

For better initial accuracy and wider temperature range, see the

ADR5040/ADR5041/ADR5043/ADR5044/ADR5045 family at
www.analog.com.

TRIM

3

04501-001

Rev. F

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2003–2010 Analog Devices, Inc. All rights reserved.

ADR525/ADR530/ADR550

TABLE OF CONTENTS

Features.............................................................................................. 1

Applications....................................................................................... 1

Pin Configuration............................................................................. 1

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

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

Specifications..................................................................................... 3

ADR525 Electrical Characteristics............................................. 3

ADR530 Electrical Characteristics............................................. 3

ADR550 Electrical Characteristics............................................. 4

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

REVISION HISTORY

8/10—Rev. E to Rev. F

Deleted ADR520 and ADR540 .........................................Universal

Changes to Table 1, Figure 1, and General Description

Section................................................................................................ 1

Deleted ADR520 Electrical Characteristics Section .................... 3

Deleted Table 2; Renumbered Sequentially .................................. 3

Deleted ADR540 Electrical Characteristics Section and

Table 5 ................................................................................................ 4

Changes to Figure 2 and Figure 7................................................... 7

Deleted Figure 3; Renumbered Sequentially................................. 8

Changes to Figure 9 and Figure 10................................................. 8

Deleted Figure 8, Figure 9, and Figure 12 ..................................... 9

Changes to Figure 20...................................................................... 10

6/08—Rev. D to Rev. E

Changes to Table 3............................................................................ 3

Changes to Table 4 and Table 5....................................................... 4

Changes to Table 6............................................................................ 5

Changes to Figure 4.......................................................................... 8

Changes to Applications Section .................................................. 11

Thermal Resistance.......................................................................5

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

Parameter Definitions.......................................................................6

Temperature Coefficient...............................................................6

Thermal Hysteresis .......................................................................6

Typical Performance Characteristics..............................................7

Theory of Operation .........................................................................9

Applications ...................................................................................9

Outline Dimensions....................................................................... 11

Ordering Guide .......................................................................... 12

12/07—Rev. C to Rev. D

Changes to Figure 3 and Figure 5....................................................8

Changes to Figure 15, Figure 16, and Figure 17 Captions ........ 10

Changes to Figure 23...................................................................... 12

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

8/07—Rev. B to Rev. C

Changes to Figure 21...................................................................... 11

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

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

1/06—Rev. A to Rev. B

Updated Formatting........................................................... Universal

Changes to Features Section ............................................................1

Changes to General Description Section .......................................1

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

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

12/03—Data Sheet Changed from Rev. 0 to Rev. A

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

Change to Ordering Guide............................................................ 14

11/03—Revision 0: Initial Version

Rev. F | Page 2 of 12

ADR525/ADR530/ADR550

SPECIFICATIONS

ADR525 ELECTRICAL CHARACTERISTICS

IIN = 50 μA to 15 mA, TA = 25°C, unless otherwise noted.

Table 2.

Parameter Symbol Conditions Min Typ Max Unit

Output Voltage V

Grade A 2.490 2.500 2.510 V

Grade B 2.495 2.500 2.505 V

Initial Accuracy V

Grade A ±0.4% −10 +10 mV

Grade B ±0.2% −5 +5 mV

Temperature Coefficient1 TCVO −40°C < TA < +85°C

Grade A 25 70 ppm/°C

Grade B 15 40 ppm/°C

Output Voltage Change vs. IIN ∆VR IIN = 0.1 mA to 15 mA 1 mV

−40°C < TA < +85°C 4 mV
I
Dynamic Output Impedance (∆VR/∆IR) IIN = 0.1 mA to 15 mA 0.2 Ω
Minimum Operating Current IIN −40°C < TA < +85°C 50 μA
Voltage Noise e
Turn-On Settling Time tR 2 μs
Output Voltage Hysteresis ∆V

1

Guaranteed by design, but not production tested.

OUT

OERR

= 1 mA to 15 mA, −40°C < TA < +85°C 2 mV

IN

0.1 Hz to 10 Hz 18 μV p-p

N p-p

IIN = 1 mA 40 ppm

OUT_HYS

ADR530 ELECTRICAL CHARACTERISTICS

IIN = 50 μA to 15 mA, TA = 25°C, unless otherwise noted.

Table 3.

Parameter Symbol Conditions Min Typ Max Unit

Output Voltage V

Grade A 2.988 3.000 3.012 V

Grade B 2.994 3.000 3.006 V

Initial Accuracy V

Grade A ±0.4% −12 +12 mV

Grade B ±0.2% −6 +6 mV

Temperature Coefficient1 TCVO −40°C < TA < +85°C

Grade A 25 70 ppm/°C

Grade B 15 40 ppm/°C

Output Voltage Change vs. IIN ∆VR IIN = 0.1 mA to 15 mA 1 mV

−40°C < TA < +85°C 4 mV
I
Dynamic Output Impedance (∆VR/∆IR) IIN = 0.1 mA to 15 mA 0.2 Ω
Minimum Operating Current IIN −40°C < TA < +85°C 50 μA
Voltage Noise e
Turn-On Settling Time tR 2 μs
Output Voltage Hysteresis ∆V

1

Guaranteed by design, but not production tested.

OUT

OERR

= 1 mA to 15 mA, −40°C < TA < +85°C 2 mV

IN

0.1 Hz to 10 Hz 22 μV p-p

N p-p

IIN = 1 mA 40 ppm

OUT_HYS

Rev. F | Page 3 of 12

ADR525/ADR530/ADR550

ADR550 ELECTRICAL CHARACTERISTICS

IIN = 50 μA to 15 mA, TA = 25°C, unless otherwise noted.

Table 4.

Parameter Symbol Conditions Min Typ Max Unit

Output Voltage V

Grade A 4.980 5.000 5.020 V
Grade B 4.990 5.000 5.010 V

Initial Accuracy V

Grade A ±0.4% −20 +20 mV
Grade B ±0.2% −10 +10 mV

Temperature Coefficient1 TCVO −40°C < TA < +85°C

Grade A 25 70 ppm/°C
Grade B 15 40 ppm/°C

Output Voltage Change vs. IIN ∆VR IIN = 0.1 mA to 15 mA 1 mV

−40°C < TA < +85°C 5 mV
I
Dynamic Output Impedance (∆VR/∆IR) IIN = 0.1 mA to 15 mA 0.2 Ω
Minimum Operating Current IIN −40°C < TA < +85°C 50 μA
Voltage Noise e
Turn-On Settling Time tR 2 μs
Output Voltage Hysteresis ∆V

1

Guaranteed by design, but not production tested.

OUT

OERR

= 1 mA to 15 mA, −40°C < TA < +85°C 2 mV

IN

0.1 Hz to 10 Hz 38 μV p-p

N p-p

IIN = 1 mA 40 ppm

OUT_HYS

Rev. F | Page 4 of 12

ADR525/ADR530/ADR550

ABSOLUTE MAXIMUM RATINGS

Ratings apply at 25°C, unless otherwise noted.

THERMAL RESISTANCE

Table 5.

Parameter Rating

Reverse Current 25 mA
Forward Current 20 mA
Storage Temperature Range −65°C to +150°C
Industrial Temperature Range −40°C to +85°C
Junction Temperature Range −65°C to +150°C
Lead Temperature (Soldering, 60 sec) 300°C

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; 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.

Table 6.

Package Type θ

3-Lead SC70 (KS) 580.5 177.4 °C/W

3-Lead SOT-23-3 (RT) 270 102 °C/W

1

θJA is specified for worst-case conditions, such as for devices soldered on

circuit boards for surface-mount packages.

1

θJC Unit

JA

ESD CAUTION

Rev. F | Page 5 of 12

ADR525/ADR530/ADR550

PARAMETER DEFINITIONS

TEMPERATURE COEFFICIENT

Temperature coefficient is defined as the change in output
voltage with respect to operating temperature changes and is
normalized by the output voltage at 25°C. This parameter is
expressed in ppm/°C and is determined by the following
equation:

TCV

where:

V

OUT(T2

V

OUT(T1

V

(25°C) = V

OUT

O

) = V
) = V

ppm

⎤

⎡
⎢

⎣

=

⎥

C

° TTV

⎦

OUT

at Temperature 2.

OUT

at Temperature 1.

OUT

at 25°C.

OUT

−

)()(

TVTV

12

OUTOUT

−×°

6

×

10

(1)

)(C)25(

12

THERMAL HYSTERESIS

Thermal hysteresis is defined as the change in output voltage
after the device is cycled through temperatures ranging from
+25°C to −40°C, then to +85°C, and back to +25°C. The
following equation expresses a typical value from a sample of
parts put through such a cycle:

−°=

C)25(

VVV

__

ENDOUTOUTHYSOUT

−°

C)25(

OUT

VV

°

C)25(

_

HYSOUT

[ppm]

V

V

=

where:

V

OUT

V

OUT_END

(25°C) = V

= V

at 25°C.

OUT

at 25°C after a temperature cycle from +25°C to

OUT

−40°C, then to +85°C, and back to +25°C.

_

ENDOUTOUT

(2)

6

×

10

Rev. F | Page 6 of 12

ADR525/ADR530/ADR550

TYPICAL PERFORMANCE CHARACTERISTICS

5.5
= 25°C

T

A

5.0

4.5

4.0

3.5

3.0

2.5

2.0

REVERSE VOLTAGE (V)

1.5

1.0

0.5

0

025

MINIMUM OPERATING CURRENT (µA)

Figure 2. Reverse Characteristics and Minimum Operating Current

8

ADR550

ADR530

ADR525

50 75 100

VIN = 2V/DIV

V

= 1V/DIV

OUT

IIN = 10mA

TIME (µs)

04501-006

4µs/DIV

04501-010

Figure 5. ADR525 Turn-On Response

6

4

2

= +25°C

T

A

0

REVERSE VOLTAGE CHANGE (mV)

= +85°C

T

–2

03

A

612

915

IIN (mA)

Figure 3. ADR525 Reverse Voltage vs. Operating Current

8

7

6

5

4

3

2

REVERSE VOLTAGE CHANGE (mV)

1

0

06

TA = –40°C

39

T

= +25°C

A

IIN (mA)

= +85°C

T

A

12 15

Figure 4. ADR550 Reverse Voltage vs. Operating Current

T

= –40°C

A

VIN = 2V/DIV

V

= 1V/DIV

OUT

IIN = 100µA

04501-008

TIME (µs)

4µs/DIV

04501-011

Figure 6. ADR525 Turn-On Response

VIN = 2V/DIV

V

= 2V/DIV

OUT

IIN = 10mA

TIME (µs)

04501-009

4µs/DIV

04501-014

Figure 7. ADR550 Turn-On Response

Rev. F | Page 7 of 12

ADR525/ADR530/ADR550

2.5030

VIN = 2V/DIV

IIN = 100µA

TIME (µs)

Figure 8. ADR550 Turn-On Response

∆I = 1mA/DIV
I

= 1mA

IN

10µs/DIV

TIME (µs)

Figure 9. ADR525 Load Transient Response

V

OUT

V

OUT

= 2V/DIV

20µs/DIV

= 50mV/DIV

04501-015

04501-016

2.5025

2.5020

2.5015

2.5010

(V)

2.5005

OUT

V

2.5000

2.4995

2.4990

2.4985

2.4980
–40 –15 10 35 60 85

TEMPERATURE (°C)

Figure 11. Data for Five Parts of ADR525 V

3.0055

3.0050

3.0045

3.0040

3.0035

3.0030

(V)

OUT

3.0025

V

3.0020

3.0015

3.0010

3.0005

3.0000
–40 –15 10 35 60 85

TEMPERATURE (°C)

Figure 12. Data for Five Parts of ADR530 V

over Temperature

OUT

over Temperature

OUT

04501-018

04501-019

5.008

5.006

∆I = 1mA/DIV

= 10mA

I

IN

V

OUT

10µs/DIV

TIME (µs)

Figure 10. ADR550 Load Transient Response

= 50mV/DIV

04501-017

5.004

5.002

5.000

(V)

4.998

OUT

V

4.996

4.994

4.992

4.990

4.988
–40 –15 10 35 60 85

TEMPERATURE (°C)

Figure 13. Data for Five Parts of ADR550 V

over Temperature

OUT

04501-020

Rev. F | Page 8 of 12

ADR525/ADR530/ADR550

V

V

V

−

V

THEORY OF OPERATION

The ADR525/ADR530/ADR550 use the band gap concept to
produce a stable, low temperature coefficient voltage reference
suitable for high accuracy data acquisition components and
systems. The devices use the physical nature of a silicon transistor
base-emitter voltage (V

) in the forward-biased operating region.

BE

All such transistors have approximately a −2 mV/°C tempera­ture coefficient (TC), making them unsuitable for direct use as
low temperature coefficient references. Extrapolation of the
temperature characteristics of any one of these devices to
absolute zero (with the collector current proportional to the
absolute temperature), however, reveals that its V

approaches

BE

approximately the silicon band gap voltage. Thus, if a voltage
develops with an opposing temperature coefficient to sum the

, a zero temperature coefficient reference results. The

V

BE

ADR525/ADR530/ADR550 circuit shown in Figure 14 provides
such a compensating voltage (V1) by driving two transistors at
different current densities and amplifying the resultant V
difference (ΔV
The sum of V

, which has a positive temperature coefficient).

BE

and V1 provides a stable voltage reference over

BE

BE

temperature.

+

V1

+

•

Given these conditions, R
voltage (V
the ADR525/ADR530/ADR550, and the output voltage (V
of the ADR525/ADR530/ADR550.

Precision Negative Voltage Reference

The ADR525/ADR530/ADR550 are suitable for applications
where a precise negative voltage is desired. Figure 16 shows the
ADR525 configured to provide a negative output.

S

+ I

I

IN

R

I

IN

L

I

L

ADR550

V

OUT

04501-003

Figure 15. Shunt Reference

is determined by the supply

BIAS

), the load and operating currents (IL and IIN) of

S

)

OUT

VV

S

R

= (3)

BIAS

OUT

II

+

INL

ADR525

–2.5V

R

–

+

∆

V

BE

–

+

BE

–

V–

04501-002

Figure 14. Circuit Schematic

APPLICATIONS

The ADR525/ADR530/ADR550 are a series of precision shunt
voltage references. They are designed to operate without an
external capacitor between the positive and negative terminals.
If a bypass capacitor is used to filter the supply, the references
remain stable.

All shunt voltage references require an external bias resistor (R
between the supply voltage and the reference (see Figure 15).

sets the current that flows through the load (IL) and the

R

BIAS

reference (I

needs to be chosen based on the following considerations:

R

BIAS

• R

). Because the load and the supply voltage can vary,

IN

must be small enough to supply the minimum I

BIAS

current to the ADR525/ADR530/ADR550, even when the
supply voltage is at its minimum value and the load current
is at its maximum value.

• R

must be large enough so that IIN does not exceed

BIAS

15 mA when the supply voltage is at its maximum value
and the load current is at its minimum value.

BIAS

IN

V

S

04501-004

Figure 16. Negative Precision Reference Configuration

Output Voltage Trim

The trim terminal of the ADR525/ADR530/ADR550 can be
used to adjust the output voltage over a range of ±0.5%. This
allows systems designers to trim small system errors by setting
the reference to a voltage other than the preset output voltage.
An external mechanical or electrical potentiometer can be used
for this adjustment. Figure 17 illustrates how the output voltage
can be trimmed using the AD5273, an Analog Devices, Inc.,
10 kΩ potentiometer.

S

)

ADR530

R

V

OUT

R1

470kΩ

AD5273

POTENTIOMETER
10kΩ

Figure 17. Output Voltage Trim

04501-005

Rev. F | Page 9 of 12

ADR525/ADR530/ADR550

V

G

A

V

Stacking the ADR525/ADR530/ADR550 for User-Definable Outputs

Multiple ADR525/ADR530/ADR550 parts can be stacked to
allow the user to obtain a desired higher voltage. Figure 18 shows
three ADR550s configured to give 15 V. The bias resistor, R

BIAS

, is
chosen using Equation 3; note that the same bias current flows
through all the shunt references in series. Figure 19 shows three
ADR550s stacked to give −15 V. R

is calculated in the same

BIAS

manner as for Figure 18. Parts of different voltages can also be
added together. For example, an ADR525 and an ADR550 can
be added together to give an output of +7.5 V or −7.5 V, as
desired. Note, however, that the initial accuracy error is now the
sum of the errors of all the stacked parts, as are the temperature
coefficients and output voltage change vs. input current.

+

DD

R

+15V

ADR550
ADR550
ADR550

GND

04501-022

Figure 18. +15 V Output with Stacked ADR550s

ADR550
ADR550

ND

ADR550

–15V

R

Adjustable Precision Voltage Source

The ADR525/ADR530/ADR550, combined with a precision low
input bias op amp, such as the AD8610, can be used to output a
precise adjustable voltage. Figure 20 illustrates the implementation
of this application using the ADR525/ADR530/ADR550. The
output of the op amp, V

, is determined by the gain of the circuit,

OUT

which is completely dependent on the resistors, R1 and R2.

V

= V

OUT

(1 + R2/R1)

REF

An additional capacitor, C1, in parallel with R2, can be added to
filter out high frequency noise. The value of C1 is dependent on
the value of R2.

S

R

V

REF

DR5xx

GND

R1

AD8610

R2

C1

(OPTIONAL)

V

= V

OUT

(1+R2/R1)

REF

04501-023

Figure 20. Adjustable Voltage Source

–V

DD

04501-024

Figure 19. −15 V Output with Stacked ADR550s

Rev. F | Page 10 of 12

ADR525/ADR530/ADR550

OUTLINE DIMENSIONS

2.20

2.00

1.35

1.25

1.15

1.00

0.80

1.80

21

0.65 BSC

2.40

2.10

1.80

1.10

0.80

0.40

0.10

3

0.10 MAX

COPLANARITY

0.10

0.40

0.25

ALL DIMENSIONS COMPLIANT WITH EIAJ SC70

SEATING
PLANE

0.26

0.10

0.30

0.20

0.10

072809-A

Figure 21. 3-Lead Thin Shrink Small Outline Transistor Package [SC70]

(KS-3)

Dimensions shown in millimeters

3.04

2.90

2.80

1.40

1.30

1.20

1.02

0.95

0.88

0.100

0.013

SEATING

PLANE

0.60

0.45

3

1

2.05

1.78

2.64

2.10

2

1.03

0.89

0.54
REF

0.60 MAX

0.30 MIN

0.51

0.37

1.12

0.89

GAUGE

PLANE

0.180

0.085

0.25

COMPLIANT TO JEDEC STANDARDS TO -236-AB

Figure 22. 3-Lead Small Outline Transistor Package [SOT-23-3]

(RT-3)

Dimensions shown in millimeters

Rev. F | Page 11 of 12

011909-C

ADR525/ADR530/ADR550

ORDERING GUIDE

Initial

Model1

Output
Voltage (V)

Accuracy
(mV)

ADR525ART-REEL7 2.5 10 70 3-Lead SOT-23-3 RT-3 RRA 3,000 −40°C to +85°C
ADR525ARTZ-R2 2.5 10 70 3-Lead SOT-23-3 RT-3 R1W 250 −40°C to +85°C
ADR525ARTZ-REEL7 2.5 10 70 3-Lead SOT-23-3 RT-3 R1W 3,000 −40°C to +85°C
ADR525BKSZ-REEL7 2.5 5 40 3-Lead SC70 KS-3 R1N 3,000 −40°C to +85°C
ADR525BRTZ-REEL7 2.5 5 40 3-Lead SOT-23-3 RT-3 R1N 3,000 −40°C to +85°C
ADR530ARTZ-REEL7 3.0 12 70 3-Lead SOT-23-3 RT-3 R1X 3,000 −40°C to +85°C
ADR530BKSZ-REEL7 3.0 6 40 3-Lead SC70 KS-3 R1Y 3,000 −40°C to +85°C
ADR530BRTZ-REEL7 3.0 6 40 3-Lead SOT-23-3 RT-3 R1Y 3,000 −40°C to +85°C
ADR550ARTZ-REEL7 5.0 20 70 3-Lead SOT-23-3 RT-3 R1Q 3,000 −40°C to +85°C
ADR550BRTZ-REEL7 5.0 10 40 3-Lead SOT-23-3 RT-3 R1P 3,000 −40°C to +85°C

1

Z = RoHS Compliant Part.

Tempco
Industrial
(ppm/°C)

Package
Description

Package
Option Branding

Ordering
Qty

Temperature
Range

©2003–2010 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D04501-0-8/10(F)

Rev. F | Page 12 of 12