Analog Devices ADR291 2 c Datasheet

Low Noise Micropower

2.5 V and 4.096 V

Precision Voltage References

ADR291/ADR292

FEATURES
Supply Range

2.8 V to 15 V, ADR291

4.4 V to 15 V, ADR292
Supply Current 12 A Max
Low-Noise 8 V and 12 V p-p (0.1 Hz to 10 Hz)
High Output Current 5 mA
Temperature Range 40C to 125C
Pin Compatible with REF02/REF19x

APPLICATIONS
Portable Instrumentation
Precision Reference for 3 V and 5 V Systems
A/D and D/A Converter Reference
Solar-Powered Applications
Loop-Current-Powered Instruments

GENERAL DESCRIPTION

The ADR291 and ADR292 are low noise, micro-power precision
voltage references that use an XFET

®

reference circuit. The new
XFET architecture offers significant performance improvements
over traditional band gap and buried Zener based references.
Improvements include one quarter the voltage noise output of
band gap references operating at the same current, very low and
ultralinear temperature drift, low thermal hysteresis, and excellent
long-term stability.

The ADR29x family are series voltage references providing stable
and accurate output voltages from supplies as low as 2.8 V for the
ADR291. Output voltage options are 2.5 V and 4.096 V for the
ADR291 and ADR292, respectively. Quiescent current is only

PIN CONFIGURATIONS

8-Lead SOIC (R-8)

NC

1

V

2

IN

(Not to Scale)

NC

3

4

GND

NC = NO CONNECT

ADR29x

TOP VIEW

8

NC

NC

7

V

6

OUT

NC

5

8-Lead TSSOP (RU-8)

NC

1

V

2

IN

(Not to Scale)

NC

3

4

GND

NC = NO CONNECT

ADR29x

TOP VIEW

8

NC

NC

7

V

6

OUT

NC

5

12 µA, making these devices ideal for battery-powered instrumen-
tation. Three electrical grades are available offering initial
output accuracies of ±2 mV, ± 3 mV, and ± 6 mV max for the
ADR291, and ±3 mV, ±4 mV, and ±6 mV max for the ADR292.
Temperature coefficients for the three grades are 8 ppm/°C,
15 ppm/°C, and 25 ppm/°C max, respectively. Line regulation and
load regulation are typically 30 ppm/V and 30 ppm/mA, main­taining the reference’s overall high performance. For a device
with 5.0 V output, refer to the ADR293 data sheet.

The ADR291 and ADR292 references are specified over the ex­tended industrial temperature range of –40°C to +125°C. Devices
are available in the 8-lead SOIC and 8-lead TSSOP packages.

ADR29x Product

Part Number Output Voltage (V) Initial Accuracy (%) Temperature Coefficient (ppm/C) Max

ADR291 2.500 0.08, 0.12, 0.24 8, 15, 25
ADR292 4.096 0.07, 0.10, 0.15 8, 15, 25
ADR293 5.000 (See ADR293 data sheet)

REV. C

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 that
may result from its use. 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 Analog Devices, Inc. All rights reserved.

ADR291/ADR292

ADR291–SPECIFICATIONS

ELECTRICAL SPECIFICATIONS

(VS = 3.0 V to 15 V, TA = 25ⴗC, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

E GRADE

Output Voltage V
Initial Accuracy V

O

OERR

I

= 0 mA 2.498 2.500 2.502 V

OUT

–2 +2 mV
–0.08 +0.08 %

F GRADE

I

Output Voltage V
Initial Accuracy V

O

OERR

= 0 mA 2.497 2.500 2.503 V

OUT

–3 +3 mV
–0.12 +0.12 %

G GRADE

I

Output Voltage V
Initial Accuracy V

O

OERR

= 0 mA 2.494 2.500 2.506 V

OUT

–6 +6 mV
–0.24 +0.24 %

LINE REGULATION

E/F Grades ∆V
G Grade 40 125 ppm/V

O

/∆V

3.0 V to 15 V, I

IN

= 0 mA 30 100 ppm/V

OUT

LOAD REGULATION

E/F Grades ∆V
G Grade 40 125 ppm/mA

LONG-TERM STABILITY ∆V

NOISE VOLTAGE e

WIDEBAND NOISE DENSITY e

O

O

N

N

/∆I

LOADVS

= 5.0 V, 0 mA to 5 mA 30 100 ppm/mA

After 1000 hrs of operation @ 125°C50 ppm

0.1 Hz to 10 Hz 8 µV p-p
@ 1 kHz 480 nV/√Hz

ELECTRICAL SPECIFICATIONS

(VS = 3.0 V to 15 V, TA = –25ⴗC ≤ TA ≤ +85ⴗC, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

TEMPERATURE COEFFICIENT

E Grade TCV
F Grade 515 ppm/°C

O

I

= 0 mA 3 8 ppm/°C

OUT

G Grade 10 25 ppm/°C

LINE REGULATION

E/F Grades ∆V
G Grade 50 150 ppm/V

O

/∆V

3.0 V to 15 V, I

IN

= 0 mA 35 125 ppm/V

OUT

LOAD REGULATION

E/F Grades ∆V
G Grade 30 150 ppm/mA

ELECTRICAL SPECIFICATIONS

/∆I

O

LOADVS

= 5.0 V, 0 mA to 5 mA 20 125 ppm/mA

(VS = 3.0 V to 15 V, TA = –40ⴗC ≤ TA ≤ +125ⴗC, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

TEMPERATURE COEFFICIENT

E Grade TCV
F Grade 520 ppm/°C

O

I

= 0 mA 3 10 ppm/°C

OUT

G Grade 10 30 ppm/°C

LINE REGULATION

E/F Grades ∆V
G Grade 70 250 ppm/V

O

/∆V

3.0 V to 15 V, I

IN

= 0 mA 40 200 ppm/V

OUT

LOAD REGULATION

E/F Grades ∆V
G Grade 30 300 ppm/mA

SUPPLY CURRENT I

THERMAL HYSTERESIS V

Specifications subject to change without notice.

O

S

O–HYS

/∆I

LOADVS

= 5.0 V, 0 mA to 5 mA 20 200 ppm/mA

TA = 25°C912µA
–40°C ≤ TA ≤ +125°C1215µA

SOIC-8, TSSOP-8 50 ppm

REV. C–2–

ADR292–SPECIFICATIONS

ADR291/ADR292

ELECTRICAL SPECIFICATIONS

(VS = 5 V to 15 V, TA = 25ⴗC, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

E GRADE

I

Output Voltage V
Initial Accuracy V

O

OERR

= 0 mA 4.093 4.096 4.099 V

OUT

–3 +3 mV
–0.07 +0.07 %

F GRADE

Output Voltage V
Initial Accuracy V

O

OERR

I

= 0 mA 4.092 4.096 4.1 V

OUT

–4 +4 mV
–0.10 +0.10 %

G GRADE

Output Voltage V
Initial Accuracy V

O

OERR

I

= 0 mA 4.090 4.096 4.102 V

OUT

–6 +6 mV
–0.15 +0.15 %

LINE REGULATION

E/F Grades ∆V

O

/∆V

4.5 V to 15 V, I

IN

= 0 mA 30 100 ppm/V

OUT

G Grade 40 125 ppm/V

LOAD REGULATION

E/F Grades ∆V

/∆I

O

LOADVS

= 5.0 V, 0 mA to 5 mA 30 100 ppm/mA

G Grade 40 125 ppm/mA

LONG-TERM STABILITY ∆V

NOISE VOLTAGE e

WIDEBAND NOISE DENSITY e

N

N

O

After 1000 hrs of operation @ 125°C50 ppm

0.1 Hz to 10 Hz 12 µV p-p
@ 1 kHz 640 nV/√Hz

ELECTRICAL SPECIFICATIONS

(VS = 5 V to 15 V, TA = –25ⴗC ≤ TA ≤ +85ⴗC, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

TEMPERATURE COEFFICIENT

I

E Grade TCV

O

= 0 mA 3 8 ppm/°C

OUT

F Grade 515 ppm/°C
G Grade 10 25 ppm/°C

LINE REGULATION

E/F Grades ∆V

O

/∆V

4.5 V to 15 V, I

IN

= 0 mA 35 125 ppm/V

OUT

G Grade 50 150 ppm/V

LOAD REGULATION

E/F Grades ∆V

/∆I

O

LOADVS

= 5.0 V, 0 mA to 5 mA 20 125 ppm/mA

G Grade 30 150 ppm/mA

ELECTRICAL SPECIFICATIONS

(VS = 5 V to 15 V, TA = –40ⴗC ≤ TA ≤ +125ⴗC, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

TEMPERATURE COEFFICIENT

I

E Grade TCV

O

= 0 mA 3 10 ppm/°C

OUT

F Grade 520 ppm/°C
G Grade 10 30 ppm/°C

LINE REGULATION

E/F Grades ∆V

O

/∆V

4.5 V to 15 V, I

IN

= 0 mA 40 200 ppm/V

OUT

G Grade 70 250 ppm/V

LOAD REGULATION

E/F Grades ∆V

/∆I

O

LOADVS

= 5.0 V, 0 mA to 5 mA 20 200 ppm/mA

G Grade 30 300 ppm/mA

SUPPLY CURRENT I

S

TA = 25°C1015µA
–40°C ≤ TA ≤ +125°C1218µA

THERMAL HYSTERESIS V

Specifications subject to change without notice.

REV. C

O–HYS

SOIC-8, TSSOP-8 50 ppm

–3–

ADR291/ADR292

ABSOLUTE MAXIMUM RATINGS

Supply Voltage ..................................................................18 V

Output Short-Circuit Duration to GND .................... Indefinite

Storage Temperature Range

SO, RU Package ...................................... ⫺65°C to 150°C

Operating Temperature Range

Package Type JA* 

JC

Unit

8-Lead SOIC (R) 158 43 °C/W
8-Lead TSSOP (RU) 240 43 °C/W

*θJA is specified for worst-case conditions, i.e., θ

testing. In practice, θ

is specified for a device soldered in the circuit board.

JA

is specified for device in socket

JA

ADR291/ADR292 ................................... ⫺40°C to 125°C

Junction Temperature Range

R, RU Package ........................................ ⫺65°C to 125°C

Lead Temperature (Soldering, 60 sec) ............................ 300°C

NOTES

1. Stresses above those listed under Absolute Maximum Ratings may
cause permanent damage to the device. This is a stress rating only; functional
operation at or above this specification is not implied. Exposure to the
above maximum rating conditions for extended periods may affect device
reliability.

2. Remove power before inserting or removing units from their sockets.

ORDERING GUIDE

Temperature Number of

Output Initial Coefficient Package Package Parts per

Model Voltage Accuracy (%) Max (ppm/ C) Description Option Package

ADR291ER 2.50 0.08 8 SOIC R-8 98
ADR291ER-REEL7 2.50 0.08 8 SOIC R-8 1000
ADR291FR 2.50 0.12 15 SOIC R-8 98
ADR291FR-REEL7 2.50 0.12 15 SOIC R-8 1000
ADR291FR-REEL 2.50 0.12 15 SOIC R-8 2500
ADR291GR 2.50 0.24 25 SOIC R-8 98
ADR291GR-REEL7 2.50 0.24 25 SOIC R-8 1000
ADR291GR-REEL 2.50 0.24 25 SOIC R-8 2500
ADR291GRU-REEL7 2.50 0.24 25 TSSOP RU-8 1000
ADR291GT9 2.50 0.24 25 TO-92 T-9 98
ADR291GT9-REEL 2.50 0.24 25 TO-92 T-9 2000

ADR292ER 4.096 0.07 8 SOIC R-8 98
ADR292ER-REEL 4.096 0.07 8 SOIC R-8 2500
ADR292FR 4.096 0.10 15 SOIC R-8 98
ADR292FR-REEL7 4.096 0.10 15 SOIC R-8 1000
ADR292FR-REEL 4.096 0.10 15 SOIC R-8 2500
ADR292GR 4.096 0.15 25 SOIC R-8 98
ADR292GR-REEL7 4.096 0.15 25 SOIC R-8 1000
ADR292GRU 4.096 0.24 25 TSSOP RU-8 98
ADR292GRU-REEL7 4.096 0.15 25 TSSOP RU-8 1000

See ADR293 data sheet for ordering guide.

OTHER XFET PRODUCTS

Part Nominal Output Package
Number Voltage (V) Type

ADR420 2.048 8-Lead MSOP/SOIC
ADR421 2.50 8-Lead MSOP/SOIC
ADR423 3.0 8-Lead MSOP/SOIC
ADR425 5.0 8-Lead MSOP/SOIC

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the ADR291/ADR292 features proprietary ESD protection circuitry, permanent
damage may occur on devices subjected to high-energy electrostatic discharges. Therefore, proper
ESD precautions are recommended to avoid performance degradation or loss of functionality.

REV. C–4–

ADR291/ADR292

PARAMETER DEFINITIONS
Line Regulation

The change in output voltage due to a specified change in input
voltage. It includes the effects of self-heating. Line regulation is
expressed in either percent-per-volt, parts-per-million-per-volt,
or microvolts-per-volt change in input voltage.

Load Regulation

The change in output voltage is due to a specified change in
load current. It includes the effects of self-heating. Load
regulation is expressed in either microvolts-per-milliampere,
parts-per-million-per-milliampere, or ohms of dc output resistance.

Long-Term Stability

Typical shift of output voltage at 25°C on a sample of parts
subjected to a test of 1000 hours at 125°C.

∆∆VVtVt

=×()– ()

OO

V ppm

O

0O1

Vt Vt

()– ()

OO

[] 10

01

=

Vt

O

()

0

6

where:

V

(t0) = VO at 25°C at time 0

O

V

(t1) = VO at 25°C after 1000 hours operation at 125°C

O

Temperature Coefficient

The change of output voltage over the operating temperature
change and normalized by the output voltage at 25°C, ex­pressed in ppm/°C. The equation follows:

TCV ppm C

[/]

O

°=

OO

VCTT

()(–)

°×

25

O

21

6

×

10

VT VT

()– ()

21

where:

V

(25°C) = VO at 25°C

O

V

) = VO at Temperature 1

O(T1

V

) = VO at Temperature 2

O(T2

Thermal Hysteresis

Thermal hysteresis is defined as the change of output voltage
after the device is cycled through temperature from +25°C to
–40°C to +85°C and back to +25°C. This is a typical value from
a sample of parts put through such a cycle.

=°

VVCV

O HYS O O TC

–_

V ppm

O HYS

–

25

()–

VCV

=

[]

°

25

()–

OOTC

VC

()

O

25

_

°

6

×

10

where:

V

(25°C) = VO at 25°C

O

V

= VO at 25°C after temperature cycle at +25°C to

O–TC

–40°C to +85°C and back to +25°C

NC = No Connect.
There are in fact internal connections at NC pins that are re­served for manufacturing purposes. Users should not connect
anything at NC pins.

REV. C

–5–