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: 15 μA maximum
Low noise: 8 μV and 12 μV 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
CONNECTION DIAGRAMS
NC
1
V
IN 2
NC
3
NC = NO CONNECT
Figure 1. 8-Lead SOIC (R-8)
NC
V
IN
1
2
3
4
ADR291/
ADR292
TOP VIEW
(Not to Scale)
8
7
6
5
NC
NC
V
OUT
00163-002
APPLICATIONS
Portable instrumentation
Precision reference for 3 V and 5 V systems
Analog-to-digital and digital-to-analog converter reference
Solar-powered applications
Loop-current-powered instruments
NC
GND
NC
NC = NO CONNECT
Figure 2. 8-Lead TSSOP (RU-8)
GND
V
OUT
V
IN
3
2
1
ADR291
TOP VIEW
(Not to Scale)
00163-003
Figure 3. 3-Lead TO-92 (T-3)
GENERAL DESCRIPTION
The ADR291 and ADR292 are low noise, micropower 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 ADR291/ADR292 family is a series of 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 12 μA, making these devices ideal for
battery-powered instrumentation. Three electrical grades are
available offering initial output accuracies of ±2 mV, ±3 mV,
and ±6 mV maximum for the ADR291, and ±3 mV, ±4 mV,
and ±6 mV maximum for the ADR292. Temperature
coefficients for the three grades are 8 ppm/°C, 15 ppm/°C, and
25 ppm/°C maximum, 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, 8-lead TSSOP, and
3-lead TO-92 packages.
Table 1. ADR291/ADR292 Product
Output
Voltage (V)
2.500
4.096
Initial
Accuracy (±%)
0.08, 0.12, 0.24
0.07, 0.10, 0.15
Temperature
Coefficient
(ppm/°C) Max
8, 15, 25
8, 15, 25
Part No.
ADR291
ADR292
Rev. E
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. 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: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2007 Analog Devices, Inc. All rights reserved.
00163-001
V
OUT
TOP VIEW
(Not to Scale)
5
NC
GND
4
6
ADR291/
ADR292
8
7
NC
NC
ADR291/ADR292
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Connection Diagrams...................................................................... 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
ADR291 Electrical Specifications............................................... 3
ADR292 Electrical Specifications............................................... 4
Absolute Maximum Ratings............................................................ 6
ESD Caution.................................................................................. 6
Pin Configurations and Function Descriptions ........................... 7
Typical Performance Characteristics ............................................. 8
Terminology .................................................................................... 12
Theory of Operation ...................................................................... 13
Device Power Dissipation Considerations.............................. 13
Basic Voltage Reference Connections ..................................... 13
Noise Performance ..................................................................... 13
Turn-On Time ............................................................................ 13
Applications Information .............................................................. 14
Negative Precision Reference Without Precision Resistors.. 14
Precision Current Source .......................................................... 14
High Voltage Floating Current Source .................................... 14
Kelvin Connections.................................................................... 15
Low Power, Low Voltage Reference for Data Converters ..... 15
Voltage Regulator for Portable Equipment ............................. 15
Outline Dimensions ....................................................................... 16
Ordering Guide .......................................................................... 17
REVISION HISTORY
12/07—Rev. D to Rev. E
Changes to Features.......................................................................... 1
Changes to Figure 34...................................................................... 14
3/06—Rev. C to Rev. D
Updated Format..................................................................Universal
Change to Table 8 ............................................................................. 6
Updated Outline Dimensions ....................................................... 15
Changes to Ordering Guide .......................................................... 16
9/03—Rev. B to Rev. C
Deleted ADR290.................................................................Universal
Changes to Specifications.................................................................2
Changes to Ordering Guide .............................................................4
Updated Outline Dimensions....................................................... 13
Rev. E | Page 2 of 20
ADR291/ADR292
SPECIFICATIONS
ADR291 ELECTRICAL SPECIFICATIONS
V
S
= 3.0 V to 15 V, T
A
= 25°C, unless otherwise noted.
Table 2.
Parameter
E GRADE
Output Voltage
Initial Accuracy
F GRADE
Output Voltage
Initial Accuracy
G GRADE
Output Voltage
Initial Accuracy
LINE REGULATION
E/F Grades
G Grade
LOAD REGULATION
E/F Grades
G Grade
LONG-TERM STABILITY
NOISE VOLTAGE
WIDEBAND NOISE DENSITY
Symbol
V
OUT
V
OERR
Conditions
I
OUT
= 0 mA
Min
2.498
–2
–0.08
2.497
–3
–0.12
2.494
–6
–0.24
Typ
2.500
Max
2.502
+2
+0.08
2.503
+3
+0.12
2.506
+6
+0.24
100
125
100
125
Unit
V
mV
%
V
mV
%
V
mV
%
ppm/V
ppm/V
ppm/mA
ppm/mA
ppm
μV p-p
nV/√Hz
V
OUT
V
OERR
I
OUT
= 0 mA
2.500
V
OUT
V
OERR
I
OUT
= 0 mA
2.500
∆V
OUT
/∆V
IN
I
OUT
= 0 mA
30
40
30
40
50
8
480
∆V
OUT
/∆I
LOAD
∆V
OUT
e
N
e
N
V
S
= 5.0 V, I
OUT
= 0 mA to 5 mA
After 1000 hours of operation @ 125°C
0.1 Hz to 10 Hz
@ 1 kHz
V
S
= 3.0 V to 15 V, T
A
= −25°C to +85°C, unless otherwise noted.
Table 3.
Parameter
TEMPERATURE COEFFICIENT
E Grade
F Grade
G Grade
LINE REGULATION
E/F Grades
G Grade
LOAD REGULATION
E/F Grades
G Grade
Symbol
TCV
OUT
Conditions
I
OUT
= 0 mA
Min
Typ
3
5
10
35
50
20
30
Max
8
15
25
125
150
125
150
Unit
ppm/°C
ppm/°C
ppm/°C
ppm/V
ppm/V
ppm/mA
ppm/mA
∆V
OUT
/∆V
IN
I
OUT
= 0 mA
∆V
OUT
/∆I
LOAD
V
S
= 5.0 V, I
OUT
= 0 mA to 5 mA
Rev. E | Page 3 of 20
ADR291/ADR292
V
S
= 3.0 V to 15 V, T
A
= −40°C to+125°C, unless otherwise noted.
Table 4.
Parameter
TEMPERATURE COEFFICIENT
E Grade
F Grade
G Grade
LINE REGULATION
E/F Grades
G Grade
LOAD REGULATION
E/F Grades
G Grade
SUPPLY CURRENT
THERMAL HYSTERESIS
Symbol
TCV
OUT
Conditions
I
OUT
= 0 mA
Min
Typ
3
5
10
40
70
20
30
9
12
50
Max
10
20
30
200
250
200
300
12
15
Unit
ppm/°C
ppm/°C
ppm/°C
ppm/V
ppm/V
ppm/mA
ppm/mA
μA
μA
ppm
∆V
OUT
/∆V
IN
I
OUT
= 0 mA
∆V
OUT
/∆I
LOAD
I
S
V
OUT-HYS
V
S
= 5.0 V, I
OUT
= 0 mA to 5 mA
T
A
= 25°C
−40°C ≤ T
A
≤ +125°C
8-lead SOIC, 8-lead TSSOP
ADR292 ELECTRICAL SPECIFICATIONS
V
S
= 5 V to 15 V, T
A
= 25°C, unless otherwise noted.
Table 5.
Parameter
E GRADE
Output Voltage
Initial Accuracy
F GRADE
Output Voltage
Initial Accuracy
G GRADE
Output Voltage
Initial Accuracy
LINE REGULATION
E/F Grades
G Grade
LOAD REGULATION
E/F Grades
G Grade
LONG-TERM STABILITY
NOISE VOLTAGE
WIDEBAND NOISE DENSITY
Symbol
V
OUT
V
OERR
Conditions
I
OUT
= 0 mA
Min
4.093
−3
−0.07
4.092
−4
−0.10
4.090
−6
−0.15
Typ
4.096
Max
4.099
+3
+0.07
4.1
+4
+0.10
4.102
+6
+0.15
100
125
100
125
Unit
V
mV
%
V
mV
%
V
mV
%
ppm/V
ppm/V
ppm/mA
ppm/mA
ppm
μV p-p
nV/√Hz
V
OUT
V
OERR
I
OUT
= 0 mA
4.096
V
OUT
V
OERR
I
OUT
= 0 mA
4.096
∆V
OUT
/∆V
IN
V
S
= 4.5 V to 15 V, I
OUT
= 0 mA
30
40
30
40
50
12
640
∆V
OUT
/∆I
LOAD
∆V
OUT
e
N
e
N
V
S
= 5.0 V, I
OUT
= 0 mA to 5 mA
After 1000 hours of operation @
125°C
0.1 Hz to 10 Hz
@ 1 kHz
Rev. E | Page 4 of 20
ADR291/ADR292
V
S
= 5 V to 15 V, T
A
= −25°C to +85°C, unless otherwise noted.
Table 6.
Parameter
TEMPERATURE COEFFICIENT
E Grade
F Grade
G Grade
LINE REGULATION
E/F Grades
G Grade
LOAD REGULATION
E/F Grades
G Grade
Symbol
TCV
OUT
Conditions
I
OUT
= 0 mA
Min
Typ
3
5
10
35
50
20
30
Max
8
15
25
125
150
125
150
Unit
ppm/°C
ppm/°C
ppm/°C
ppm/V
ppm/V
ppm/mA
ppm/mA
∆V
OUT
/ΔV
IN
V
S
= 4.5 V to 15 V, I
OUT
= 0 mA
∆V
OUT
/∆I
LOAD
V
S
= 5.0 V, I
OUT
= 0 mA to 5 mA
V
S
= 5 V to 15 V, T
A
= −40°C to +125°C, unless otherwise noted.
Table 7.
Parameter
TEMPERATURE COEFFICIENT
E Grade
F Grade
G Grade
LINE REGULATION
E/F Grades
G Grade
LOAD REGULATION
E/F Grades
G Grade
SUPPLY CURRENT
THERMAL HYSTERESIS
Symbol
TCV
OUT
Conditions
I
OUT
= 0 mA
Min
Typ
3
5
10
40
70
20
30
10
12
50
Max
10
20
30
200
250
200
300
15
18
Unit
ppm/°C
ppm/°C
ppm/°C
ppm/V
ppm/V
ppm/mA
ppm/mA
μA
μA
ppm
∆V
OUT
/∆V
IN
V
S
= 4.5 V to 15 V, I
OUT
= 0 mA
∆V
OUT
/∆I
LOAD
I
S
V
OUT-HYS
V
S
= 5.0 V, I
OUT
= 0 mA to 5 mA
T
A
= 25°C
−40°C ≤ T
A
≤ +125°C
8-lead SOIC, 8-lead TSSOP
Rev. E | Page 5 of 20
