Micropower, High Accuracy
Voltage References
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
FEATURES
PIN CONFIGURATION
Initial accuracy: ±0.1% (maximum)
Maximum temperature coefficient: 8 ppm/°C
Operating temperature range: −40°C to +125°C
Output current: +10 mA source/−3 mA sink
Low quiescent current: 100 μA (maximum)
Low dropout voltage: 250 mV at 2 mA
Output noise (0.1 Hz to 10 Hz): <10 μV p-p at 1.2 V (typical)
6-lead SOT-23
GND FORCE 1
6
VOUT FORCE
5
VOUT SENSE
GND SENSE 2
TOP VIEW
ENABLE 3 (Not to Scale) 4 VIN
08440-001
ADR34xx
Figure 1. 6-Lead SOT-23
APPLICATIONS
Precision data acquisition systems
Industrial instrumentation
Medical devices
Battery-powered devices
GENERAL DESCRIPTION
The ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/
ADR3440/ADR3450 are low cost, low power, high precision
CMOS voltage references, featuring ±0.1% initial accuracy, low
operating current, and low output noise in a small SOT-23
package. For high accuracy, output voltage and temperature
coefficient are trimmed digitally during final assembly using
Analog Devices, Inc., patented DigiTrim® technology.
Stability and system reliability are further improved by the low
output voltage hysteresis of the device and low long-term output
voltage drift. Furthermore, the low operating current of the
device (100 μA maximum) facilitates usage in low power
devices, and its low output noise helps maintain signal integrity
in critical signal processing systems.
Table 2. Voltage Reference Choices from Analog Devices
VOUT
(V)
0.5/1.0
1.2
2.048
2.5
3.0
These CMOS are available in a wide range of output voltages, all
of which are specified over the industrial temperature range of
−40°C to +125°C.
3.3
Table 1. Selection Guide
4.096
Model
ADR3412
ADR3420
ADR3425
ADR3430
ADR3433
ADR3440
ADR3450
Output Voltage (V)
1.200
2.048
2.500
3.000
3.300
4.096
5.000
Input Voltage Range (V)
2.3 to 5.5
2.3 to 5.5
2.7 to 5.5
3.2 to 5.5
3.5 to 5.5
4.3 to 5.5
5.2 to 5.5
5.0
10.0
Low Cost/
Low Power
ADR3412
ADR280
ADR360
ADR3420
ADR3425
AD1582
ADR361
ADR3430
AD1583
ADR363
ADR366
ADR3433
ADR3440
AD1584
ADR364
ADR3450
AD1585
ADR365
High Voltage,
High Performance
Ultralow
Power
Low
Noise
ADR130
REF191
ADR291
REF192
ADR430
ADR440
ADR431
ADR441
ADR03
AD780
REF193
ADR433
ADR06
ADR443
AD780
REF196
ADR292
ADR434
REF198
ADR293
REF195
ADR444
ADR435
ADR445
ADR02
AD586
ADR01
AD587
Rev. B
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
©2010 Analog Devices, Inc. All rights reserved.
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
TABLE OF CONTENTS
Features .............................................................................................. 1 ESD Caution................................................................................ 10 Applications ....................................................................................... 1 Pin Configuration and Function Descriptions........................... 11 Pin Configuration ............................................................................. 1 Typical Performance Characteristics ........................................... 12 General Description ......................................................................... 1 Terminology .................................................................................... 18 Revision History ............................................................................... 2 Theory of Operation ...................................................................... 19 Specifications..................................................................................... 3 Power Dissipation....................................................................... 19 ADR3412 Electrical Characteristics .......................................... 3 Applications Information .............................................................. 20 ADR3420 Electrical Characteristics .......................................... 4 Basic Voltage Reference Connection ....................................... 20 ADR3425 Electrical Characteristics .......................................... 5 Input and Output Capacitors .................................................... 20 ADR3430 Electrical Characteristics .......................................... 6 4-Wire Kelvin Connections ...................................................... 20 ADR3433 Electrical Characteristics .......................................... 7 VIN Slew Rate Considerations ................................................... 20 ADR3440 Electrical Characteristics .......................................... 8 Shutdown/Enable Feature ......................................................... 20 ADR3450 Electrical Characteristics .......................................... 9 Sample Applications ................................................................... 21 Absolute Maximum Ratings and Minimum Operating
Condition ......................................................................................... 10 Outline Dimensions ....................................................................... 22 Ordering Guide .......................................................................... 22 Thermal Resistance .................................................................... 10 REVISION HISTORY
6/10—Rev. A to Rev. B
Added ADR3412, ADR3420, ADR3433 ..................... Throughout
Changes to Table 1 and Table 2 ....................................................... 1
Added ADR3412 Electrical Characteristics Section
and Table 3 ......................................................................................... 3
Added ADR3420 Electrical Characteristics Section
and Table 4 ......................................................................................... 4
Added ADR3433 Electrical Characteristics Section and
Table 7, Renumbered Subsequent Tables ...................................... 7
Replaced Figure 5 Through Figure 7 ........................................... 12
Replaced Figure 11 Through Figure 13 ....................................... 13
4/10—Rev. 0 to Rev. A
Added ADR3430 and ADR3440 ....................................... Universal
Changes to Table 1, Table 2, and Figure 1 ..................................... 1
Changes to Table 3 ............................................................................ 3
Added ADR3430 Electrical Characteristics Section .....................4
Added Table 4; Renumbered Sequentially .....................................4
Added ADR3440 Electrical Characteristics Section and
Table 5 .................................................................................................5
Changes to Table 6.............................................................................6
Changes to Figure 2 ...........................................................................8
Changes to Figure 4 and Figure 5 ....................................................9
Changes to Figure 11...................................................................... 10
Changes to Figure 36 and Figure 37 Caption ............................. 14
Changes to Figure 39 and Theory of Operation Section .......... 16
Changes to Figure 40 and Figure 41............................................. 17
Changes to Negative Reference Section, Boosted Output
Current Reference Section, Figure 43, and Figure 44 ................ 18
Changes to Ordering Guide .......................................................... 19
3/10—Revision 0: Initial Version
Rev. B | Page 2 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
SPECIFICATIONS
ADR3412 ELECTRICAL CHARACTERISTICS
VIN = 2.3 V to 5.5 V, TA = 25°C, ILOAD = 0 mA, unless otherwise noted.
Table 3.
Parameter
OUTPUT VOLTAGE
INITIAL ACCURACY
Symbol
VOUT
VOERR
Conditions
TEMPERATURE COEFFICIENT
LINE REGULATION
TCVOUT
ΔVO/ΔVIN
−40°C ≤ TA ≤ +125°C
VIN = 2.3 V to 5.5 V
VIN = 2.3 V to 5.5 V, −40°C ≤ TA ≤ +125°C
LOAD REGULATION
Sourcing
ΔVO/ΔIL
VIN = 2.8 V to 5.5 V
VIN = 2.8 V to 5.5 V
ENABLE PIN
Shutdown Voltage
ENABLE Voltage
ENABLE Pin Leakage Current
OUTPUT VOLTAGE NOISE
VL
VH
IEN
en p-p
2
Unit
V
%
mV
ppm/°C
ppm/V
ppm/V
14
30
ppm/mA
7
50
ppm/mA
10
−3
mA
mA
IQ
VDO
1
Max
1.2012
±0.1
±1.2
8
50
160
IL
Shutdown
DROPOUT VOLTAGE 1
OUTPUT VOLTAGE NOISE
DENSITY
OUTPUT VOLTAGE HYSTERESIS 2
RIPPLE REJECTION RATIO
LONG-TERM STABILITY
TURN-ON SETTLING TIME
Typ
1.2000
7
IL = 0 mA to 10 mA,
VIN = 2.8 V, −40°C ≤ TA ≤ +125°C
IL = 0 mA to −3 mA,
VIN = 2.8 V, −40°C ≤ TA ≤ +125°C
Sinking
OUTPUT CURRENT CAPACITY
Sourcing
Sinking
QUIESCENT CURRENT
Normal Operation
Min
1.1988
ENABLE > VIN × 0.85
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
ENABLE < 0.7 V
IL = 0 mA, −40°C ≤ TA ≤ +125°C
IL = 2 mA, −40°C ≤ TA ≤ +125°C
1
1
0
VIN × 0.85
en
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
f = 0.1 Hz to 10 Hz
f = 10 Hz to 10 kHz
f = 1 kHz
0.85
8
28
0.6
ΔVOUT_HYS
RRR
ΔVOUT_LTD
tR
TA = +25°C to −40°C to +125°C to +25°C
fIN = 60 Hz
1000 hours at 50°C
CIN = 0.1 μF, CL = 0.1 μF, RLoad = 1 kΩ
70
−60
30
100
Refers to the minimum difference between VIN and VOUT such that VOUT maintains a minimum accuracy of 0.1%. See the Terminology section.
See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.
Rev. B | Page 3 of 24
85
100
5
1.1
1.15
μA
μA
μA
V
V
0.7
VIN
3
V
V
μA
μV p-p
μV rms
μV/√Hz
ppm
dB
ppm
μs
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
ADR3420 ELECTRICAL CHARACTERISTICS
VIN = 2.3 V to 5.5 V, TA = 25°C, ILOAD = 0 mA, unless otherwise noted.
Table 4.
Parameter
OUTPUT VOLTAGE
INITIAL ACCURACY
Symbol
VOUT
VOERR
Conditions
TEMPERATURE COEFFICIENT
LINE REGULATION
TCVOUT
ΔVO/ΔVIN
−40°C ≤ TA ≤ +125°C
VIN = 2.3 V to 5.5 V
VIN = 2.3 V to 5.5 V, −40°C ≤ TA ≤ +125°C
LOAD REGULATION
Sourcing
ΔVO/ΔIL
VIN = 2.8 V to 5.5 V
VIN = 2.8 V to 5.5 V
ENABLE PIN
Shutdown Voltage
ENABLE Voltage
ENABLE Pin Leakage Current
OUTPUT VOLTAGE NOISE
VL
VH
IEN
en p-p
2
Unit
V
%
mV
ppm/°C
ppm/V
ppm/V
12
30
ppm/mA
7
50
ppm/mA
10
−3
mA
mA
IQ
VDO
1
Max
2.0500
±0.1
±2.048
8
50
160
IL
Shutdown
DROPOUT VOLTAGE 1
OUTPUT VOLTAGE NOISE
DENSITY
OUTPUT VOLTAGE HYSTERESIS 2
RIPPLE REJECTION RATIO
LONG-TERM STABILITY
TURN-ON SETTLING TIME
Typ
2.0480
7
IL = 0 mA to 10 mA,
VIN = 2.8 V, −40°C ≤ TA ≤ +125°C
IL = 0 mA to −3 mA,
VIN = 2.8 V, −40°C ≤ TA ≤ +125°C
Sinking
OUTPUT CURRENT CAPACITY
Sourcing
Sinking
QUIESCENT CURRENT
Normal Operation
Min
2.0459
ENABLE > VIN × 0.85
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
ENABLE < 0.7 V
IL = 0 mA, −40°C ≤ TA ≤ +125°C
IL = 2 mA, −40°C ≤ TA ≤ +125°C
100
150
0
VIN × 0.85
en
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
f = 0.1 Hz to 10 Hz
f = 10 Hz to 10 kHz
f = 1 kHz
0.85
15
38
0.9
ΔVOUT_HYS
RRR
ΔVOUT_LTD
tR
TA = +25°C to −40°C to +125°C to +25°C
fIN = 60 Hz
1000 hours at 50°C
CIN = 0.1 μF, CL = 0.1 μF, RLoad = 1 kΩ
70
−60
30
400
Refers to the minimum difference between VIN and VOUT such that VOUT maintains a minimum accuracy of 0.1%. See the Terminology section.
See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.
Rev. B | Page 4 of 24
85
100
5
250
300
μA
μA
μA
mV
mV
0.7
VIN
3
V
V
μA
μV p-p
μV rms
μV/√Hz
ppm
dB
ppm
μs
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
ADR3425 ELECTRICAL CHARACTERISTICS
VIN = 2.7 V to 5.5 V, IL = 0 mA, TA = 25°C, unless otherwise noted.
Table 5.
Parameter
OUTPUT VOLTAGE
INITIAL ACCURACY
Symbol
VOUT
VOERR
Conditions
TEMPERATURE COEFFICIENT
LINE REGULATION
TCVOUT
ΔVO/ΔVIN
−40°C ≤ TA ≤ +125°C
VIN = 2.7 V to 5.5 V
VIN = 2.7 V to 5.5 V, −40°C ≤ TA ≤ +125°C
2.5
5
LOAD REGULATION
Sourcing
ΔVO/ΔIL
IL = 0 mA to 10 mA,
VIN = 3.0 V, −40°C ≤ TA ≤ +125°C
IL = 0 mA to −3 mA,
VIN = 3.0 V, −40°C ≤ TA ≤ +125°C
Sinking
OUTPUT CURRENT CAPACITY
Sourcing
Sinking
QUIESCENT CURRENT
Normal Operation
VIN = 3.0 V to 5.5 V
VIN = 3.0 V to 5.5 V
ENABLE PIN
Shutdown Voltage
ENABLE Voltage
ENABLE Pin Leakage Current
OUTPUT VOLTAGE NOISE
VL
VH
IEN
en p-p
2
Max
2.5025
±0.1
±2.5
8
50
120
Unit
V
%
mV
ppm/°C
ppm/V
ppm/V
10
30
ppm/mA
10
50
ppm/mA
10
−3
mA
mA
IQ
VDO
1
Typ
2.500
IL
Shutdown
DROPOUT VOLTAGE 1
OUTPUT VOLTAGE NOISE
DENSITY
OUTPUT VOLTAGE HYSTERESIS 2
RIPPLE REJECTION RATIO
LONG-TERM STABILITY
TURN-ON SETTLING TIME
Min
2.4975
ENABLE ≥ VIN × 0.85
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
ENABLE ≤ 0.7 V
IL = 0 mA, TA = −40°C ≤ TA ≤ +125°C
IL = 2 mA, TA = −40°C ≤ TA ≤ +125°C
50
75
0
VIN × 0.85
en
ENABLE = VIN, TA = −40°C ≤ TA ≤ +125°C
f = 0.1 Hz to 10 Hz
f = 10 Hz to 10 kHz
f = 1 kHz
1
18
42
1
ΔVOUT_HYS
RRR
ΔVOUT_LTD
tR
TA = +25°C to −40°C to +125°C to +25°C
fIN = 60 Hz
1000 hours at 50°C
CIN = 0.1 μF, CL = 0.1 μF, RLoad = 1 kΩ
70
−60
30
600
Refers to the minimum difference between VIN and VOUT such that VOUT maintains a minimum accuracy of 0.1%. See the Terminology section.
See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.
Rev. B | Page 5 of 24
85
100
5
200
250
μA
μA
μA
mV
mV
0.7
VIN
3
V
V
μA
μV p-p
μV rms
μV/√Hz
ppm
dB
ppm
μs
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
ADR3430 ELECTRICAL CHARACTERISTICS
VIN = 3.2 V to 5.5 V, IL = 0 mA, TA = 25°C, unless otherwise noted.
Table 6.
Parameter
OUTPUT VOLTAGE
INITIAL ACCURACY
Symbol
VOUT
VOERR
Conditions
TEMPERATURE COEFFICIENT
LINE REGULATION
TCVOUT
ΔVO/ΔVIN
−40°C ≤ TA ≤ +125°C
VIN = 3.2 V to 5.5 V
VIN = 3.2 V to 5.5 V, −40°C ≤ TA ≤ +125°C
2.5
5
LOAD REGULATION
Sourcing
ΔVO/ΔIL
IL = 0 mA to 10 mA,
VIN = 3.5 V, −40°C ≤ TA ≤ +125°C
IL = 0 mA to −3 mA,
VIN = 3.5 V, −40°C ≤ TA ≤ +125°C
Sinking
OUTPUT CURRENT CAPACITY
Sourcing
Sinking
QUIESCENT CURRENT
Normal Operation
VIN = 3.5 V to 5.5 V
VIN = 3.5 V to 5.5 V
Max
3.0030
±0.1
±3.0
8
50
120
Unit
V
%
mV
ppm/°C
ppm/V
ppm/V
9
30
ppm/mA
10
50
ppm/mA
10
−3
mA
mA
IQ
VDO
ENABLE PIN
Shutdown Voltage
ENABLE Voltage
ENABLE Pin Leakage Current
OUTPUT VOLTAGE NOISE
VL
VH
IEN
en p-p
OUTPUT VOLTAGE NOISE DENSITY
OUTPUT VOLTAGE HYSTERESIS 2
RIPPLE REJECTION RATIO
LONG-TERM STABILITY
TURN-ON SETTLING TIME
en
ΔVOUT_HYS
RRR
ΔVOUT_LTD
tR
2
Typ
3.0000
IL
Shutdown
DROPOUT VOLTAGE 1
1
Min
2.9970
ENABLE ≥ VIN × 0.85
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
ENABLE ≤ 0.7 V
IL = 0 mA, TA = −40°C ≤ TA ≤ +125°C
IL = 2 mA, TA = −40°C ≤ TA ≤ +125°C
50
75
0
VIN × 0.85
ENABLE = VIN, TA = −40°C ≤ TA ≤ +125°C
f = 0.1 Hz to 10 Hz
f = 10 Hz to 10 kHz
f = 1 kHz
TA = +25°C to −40°C to +125°C to +25°C
fIN = 60 Hz
1000 hours at 50°C
CIN = 0.1 μF, CL = 0.1 μF, RLoad = 1 kΩ
0.85
22
45
1.1
70
−60
30
700
85
100
5
200
250
μA
μA
μA
mV
mV
0.7
VIN
3
V
V
μA
μV p-p
μV rms
μV/√Hz
ppm
dB
ppm
μs
Refers to the minimum difference between VIN and VOUT such that VOUT maintains a minimum accuracy of 0.1%. See the Terminology section.
See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.
Rev. B | Page 6 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
ADR3433 ELECTRICAL CHARACTERISTICS
VIN = 3.5 V to 5.5 V, IL = 0 mA, TA = 25°C, unless otherwise noted.
Table 7.
Parameter
OUTPUT VOLTAGE
INITIAL ACCURACY
Symbol
VOUT
VOERR
TEMPERATURE COEFFICIENT
LINE REGULATION
TCVOUT
ΔVO/ΔVIN
LOAD REGULATION
Sourcing
Typ
3.30
Max
3.3033
±0.1
±3.3
8
50
120
Unit
V
%
mV
ppm/°C
ppm/V
ppm/V
9
30
ppm/mA
10
50
ppm/mA
5
IL
VIN = 3.8 V to 5.5 V
VIN = 3.8 V to 5.5 V
10
−3
mA
mA
IQ
VDO
ENABLE PIN
Shutdown Voltage
ENABLE Voltage
ENABLE Pin Leakage Current
OUTPUT VOLTAGE NOISE
VL
VH
IEN
en p-p
OUTPUT VOLTAGE NOISE DENSITY
OUTPUT VOLTAGE HYSTERESIS 2
RIPPLE REJECTION RATIO
LONG-TERM STABILITY
TURN-ON SETTLING TIME
en
ΔVOUT_HYS
RRR
ΔVOUT_LTD
tR
2
−40°C ≤ TA ≤ +125°C
VIN = 3.5 V to 5.5 V
VIN = 3.5 V to 5.5 V, −40°C ≤ TA ≤ +125°C
IL = 0 mA to 10 mA,
VIN = 3.8 V, −40°C ≤ TA ≤ +125°C
IL = 0 mA to −3 mA,
VIN = 3.8 V, −40°C ≤ TA ≤ +125°C
Shutdown
DROPOUT VOLTAGE 1
1
Min
3.2967
ΔVO/ΔIL
Sinking
OUTPUT CURRENT CAPACITY
Sourcing
Sinking
QUIESCENT CURRENT
Normal Operation
Conditions
ENABLE > VIN × 0.85
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
ENABLE < 0.7 V
IL = 0 mA, −40°C ≤ TA ≤ +125°C
IL = 2 mA, −40°C ≤ TA ≤ +125°C
50
75
0
VIN × 0.85
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
f = 0.1 Hz to 10 Hz
f = 10 Hz to 10 kHz
f = 1 kHz
TA = +25°C to −40°C to +125°C to +25°C
fIN = 60 Hz
1000 hours at 50°C
CIN = 0.1 μF, CL = 0.1 μF, RLoad = 1 kΩ
0.85
25
46
1.2
70
-60
30
750
Refers to the minimum difference between VIN and VOUT such that VOUT maintains a minimum accuracy of 0.1%. See the Terminology section.
See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.
Rev. B | Page 7 of 24
85
100
5
200
250
μA
μA
μA
mV
mV
0.7
VIN
3
V
V
μA
μV p-p
μV rms
μV/√Hz
ppm
dB
ppm
μs
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
ADR3440 ELECTRICAL CHARACTERISTICS
VIN = 4.3 V to 5.5 V, IL = 0 mA, TA = 25°C, unless otherwise noted.
Table 8.
Parameter
OUTPUT VOLTAGE
INITIAL ACCURACY
Symbol
VOUT
VOERR
Conditions
TEMPERATURE COEFFICIENT
LINE REGULATION
TCVOUT
ΔVO/ΔVIN
−40°C ≤ TA ≤ +125°C
VIN = 4.3 V to 5.5 V
VIN = 4.3 V to 5.5 V, −40°C ≤ TA ≤ +125°C
2.5
3
LOAD REGULATION
Sourcing
ΔVO/ΔIL
IL = 0 mA to 10 mA,
VIN = 4.6 V, −40°C ≤ TA ≤ +125°C
IL = 0 mA to −3 mA,
VIN = 4.6 V, −40°C ≤ TA ≤ +125°C
Sinking
OUTPUT CURRENT CAPACITY
Sourcing
Sinking
QUIESCENT CURRENT
Normal Operation
VIN = 4.6 V to 5.5 V
VIN = 4.6 V to 5.5 V
ENABLE PIN
Shutdown Voltage
ENABLE Voltage
ENABLE Pin Leakage Current
OUTPUT VOLTAGE NOISE
VL
VH
IEN
en p-p
2
Max
4.1000
±0.1
±4.096
8
50
120
Unit
V
%
mV
ppm/°C
ppm/V
ppm/V
6
30
ppm/mA
15
50
ppm/mA
10
−3
mA
mA
IQ
VDO
1
Typ
4.0960
IL
Shutdown
DROPOUT VOLTAGE 1
OUTPUT VOLTAGE NOISE
DENSITY
OUTPUT VOLTAGE HYSTERESIS 2
RIPPLE REJECTION RATIO
LONG-TERM STABILITY
TURN-ON SETTLING TIME
Min
4.0919
ENABLE ≥ VIN × 0.85
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
ENABLE ≤ 0.7 V
IL = 0 mA, TA = −40°C ≤ TA ≤ +125°C
IL = 2 mA, TA = −40°C ≤ TA ≤ +125°C
50
75
0
VIN × 0.85
85
100
5
200
250
μA
μA
μA
mV
mV
0.7
VIN
3
en
ENABLE = VIN, TA = −40°C ≤ TA ≤ +125°C
f = 0.1 Hz to 10 Hz
f = 10 Hz to 10 kHz
f = 1 kHz
29
53
1.4
V
V
μA
μV p-p
μV rms
μV/√Hz
ΔVOUT_HYS
RRR
ΔVOUT_LTD
tR
TA = +25°C to −40°C to +125°C to +25°C
fIN = 60 Hz
1000 hours at 50°C
CIN = 0.1 μF, CL = 0.1 μF, RLoad = 1 kΩ
70
−60
30
800
ppm
dB
ppm
μs
Refers to the minimum difference between VIN and VOUT such that VOUT maintains a minimum accuracy of 0.1%. See the Terminology section.
See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.
Rev. B | Page 8 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
ADR3450 ELECTRICAL CHARACTERISTICS
VIN = 5.2 V to 5.5 V, IL = 0 mA, TA = 25°C, unless otherwise noted.
Table 9.
Parameter
OUTPUT VOLTAGE
INITIAL ACCURACY
Symbol
VOUT
VOERR
Conditions
TEMPERATURE COEFFICIENT
LINE REGULATION
TCVOUT
ΔVO/ΔVIN
−40°C ≤ TA ≤ +125°C
VIN = 5.2 V to 5.5 V
VIN = 5.2 V to 5.5 V, −40°C ≤ TA ≤ +125°C
2.5
3
LOAD REGULATION
Sourcing
ΔVO/ΔIL
IL = 0 mA to 10 mA,
VIN = 5.5 V, −40°C ≤ TA ≤ +125°C
IL = 0 mA to −3 mA,
VIN = 5.5 V, −40°C ≤ TA ≤ +125°C
Sinking
OUTPUT CURRENT CAPACITY
Sourcing
Sinking
QUIESCENT CURRENT
Normal Operation
VIN = 5.5 V
VIN = 5.5 V
ENABLE PIN
Shutdown Voltage
ENABLE Voltage
ENABLE Pin Leakage Current
OUTPUT VOLTAGE NOISE
VL
VH
IEN
en p-p
2
Max
5.0050
±0.1
±5.0
8
50
120
Unit
V
%
mV
ppm/°C
ppm/V
ppm/V
3
30
ppm/mA
19
50
ppm/mA
10
−3
mA
mA
IQ
VDO
1
Typ
5.0000
IL
Shutdown
DROPOUT VOLTAGE 1
OUTPUT VOLTAGE NOISE
DENSITY
OUTPUT VOLTAGE HYSTERESIS 2
RIPPLE REJECTION RATIO
LONG-TERM STABILITY
TURN-ON SETTLING TIME
Min
4.9950
ENABLE ≥ VIN × 0.85
ENABLE = VIN, −40°C ≤ TA ≤ +125°C
ENABLE ≤ 0.7 V
IL = 0 mA, TA = −40°C ≤ TA ≤ +125°C
IL = 2 mA, TA = −40°C ≤ TA ≤ +125°C
50
75
0
VIN × 0.85
en
ENABLE = VIN, TA = −40°C ≤ TA ≤ +125°C
f = 0.1 Hz to 10 Hz
f = 10 Hz to 10 kHz
f = 1 kHz
1
35
60
1.5
ΔVOUT_HYS
RRR
ΔVOUT_LTD
tR
TA = +25°C to −40°C to +125°C to +25°C
fIN = 60 Hz
1000 hours at 50°C
CIN = 0.1 μF, CL = 0.1 μF, RLoad = 1 kΩ
70
−58
30
900
Refers to the minimum difference between VIN and VOUT such that VOUT maintains a minimum accuracy of 0.1%. See the Terminology section.
See the Terminology section. The part is placed through the temperature cycle in the order of temperatures shown.
Rev. B | Page 9 of 24
85
100
5
200
250
μA
μA
μA
mV
mV
0.7
VIN
3
V
V
μA
μV p-p
μV rms
μV/√Hz
ppm
dB
ppm
μs
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
ABSOLUTE MAXIMUM RATINGS AND MINIMUM OPERATING CONDITION
TA = 25°C, unless otherwise noted.
THERMAL RESISTANCE
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Table 10.
Parameter
Supply Voltage
ENABLE to GND SENSE Voltage
VIN Minimum Slew Rate
Operating Temperature Range
Storage Temperature Range
Junction Temperature Range
Rating
6V
VIN
0.1 V/ms
−40°C to +125°C
−65°C to +125°C
−65°C to +150°C
Table 11. Thermal Resistance
Package Type
6-Lead SOT-23 (RJ-6)
ESD CAUTION
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.
Rev. B | Page 10 of 24
θJA
230
θJC
92
Unit
°C/W
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
GND FORCE 1
6
VOUT FORCE
5
VOUT SENSE
ADR34xx
GND SENSE 2
TOP VIEW
ENABLE 3 (Not to Scale) 4 VIN
08440-002
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 2. Pin Configuration
Table 12. Pin Function Descriptions
Pin No.
1
2
3
4
5
6
1
Mnemonic
GND FORCE
GND SENSE
ENABLE
VIN
VOUT SENSE
VOUT FORCE
Description
Ground Force Connection. 1
Ground Voltage Sense Connection. Connect directly to the point of lowest potential in the application.1
Enable Connection. Enables or disables the device.
Input Voltage Connection.
Reference Voltage Output Sensing Connection. Connect directly to the voltage input of the load devices.1
Reference Voltage Output.1
See the Applications Information section for more information on force/sense connections.
Rev. B | Page 11 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25°C, unless otherwise noted.
2.5010
5.0025
5.0010
OUTPUT VOLTAGE (V)
5.0015
2.5004
2.5002
2.5000
2.4998
2.4996
5.0005
5.0000
4.9995
4.9990
2.4994
4.9985
2.4992
4.9980
–25
–10
5
20
35
50
65
80
95
110
125
TEMPERATURE (ºC)
08440-003
4.9975
–40
5
20
35
50
65
80
95
110
125
Figure 6. ADR3450 Output Voltage vs. Temperature
40
45
35
40
35
NUMBER OF DEVICES
30
25
20
15
10
30
25
20
15
10
5
5
0
1
2
3
4
5
6
7
8
9
TEMPERATURE COEFFICIENT (ppm/°C)
10
11
0
08440-005
0
0
1
2
3
4
5
6
7
8
9
10 MORE
TEMPERATURE COEFFICIENT (ppm/°C)
Figure 4. ADR3425 Temperature Coefficient Distribution
08440-006
NUMBER OF DEVICES
–10
TEMPERATURE (ºC)
Figure 3. ADR3425 Output Voltage vs. Temperature
Figure 7. ADR3450 Temperature Coefficient Distribution
24
35
ADR3412
ADR3420
ADR3425
ADR3430
ADR3433
ADR3440
ADR3450
20
18
16
IL = 0mA TO +10mA
SOURCING
14
12
10
8
6
08440-053
4
2
0
–40
–25
–10
5
20
50
65
35
TEMPERATURE (°C)
80
95
110
ADR3412
ADR3420
ADR3425
ADR3430
ADR3433
ADR3440
ADR3450
30
LOAD REGULATION (ppm/mA)
22
LOAD REGULATION (ppm/mA)
–25
25
20
15
10
5
–40
125
Figure 5. Load Regulation vs. Temperature (Sourcing)
IL = 0mA TO –3mA
SINKING
08440-054
OUTPUT VOLTAGE (V)
2.5006
2.4990
–40
VIN = 5.5V
5.0020
–25
–10
5
20
35
50
65
TEMPERATURE (°C)
80
95
110
Figure 8. Load Regulation vs. Temperature (Sinking)
Rev. B | Page 12 of 24
125
08440-004
VIN = 5.5V
2.5008
1.20
400
1.15
350
DIFFERENTIAL VOLTAGE (mV)
1.05
1.00
0.95
0.90
0.80
–3
–2
–1
0
1
2
3
4
5
6
7
8
9
250
200
150
100
50
08440-056
0.85
300
0
–3
10
–2
–1
0
1
3
4
5
6
7
8
9
10
10
125
LOAD CURRENT (mA)
LOAD CURRENT (mA)
Figure 9. ADR3412 Dropout Voltage vs. Load Current
Figure 12. ADR3425 Dropout Voltage vs. Load Current
450
350
–40°C
+25°C
+125°C
400
300
300
DIFFERENTIAL VOLTAGE (mV)
350
DIFFERENTIAL VOLTAGE (mV)
2
08440-015
TA = –40°C
TA = +25°C
TA = +125°C
08440-016
1.10
–40°C
+25°C
+125°C
08440-052
DIFFERENTIAL VOLTAGE (V)
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
TA = –40°C
TA = +25°C
TA = +125°C
250
200
150
100
0
–50
–3
–2
–1
0
1
2
3
4
5
6
7
8
9
200
150
100
50
08440-057
50
250
0
–3
10
–2
–1
0
1
LOAD CURRENT (mA)
2
3
4
5
6
7
8
9
LOAD CURRENT (mA)
Figure 13. ADR3450 Dropout Voltage vs. Load Current
Figure 10. ADR3420 Dropout Voltage vs. Load Current
140
FREQUENCY GEN = 1Hz
LINE REGULATION (ppm/V)
120
VIN = 2V/DIV
CIN = COUT = 0.1µF
RL = 1kΩ
2
VOUT = 500mV/DIV
CH1 500mV
CH2 2.00V
M100µs
A CH2
80
60
40
20
08440-055
1
100
ADR3412
ADR3420
ADR3425
ADR3430
ADR3433
ADR3440
ADR3450
0
–40 –25
2.36V
–10
5
20
35
50
65
80
95
TEMPERATURE (°C)
Figure 14. Line Regulation vs. Temperature
Figure 11. ADR3412 Start-Up (Turn-On Settle) Time
Rev. B | Page 13 of 24
110
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
1
08440-028
10µV/DIV
TIME = 1s/DIV
CH1 pk-pk = 18µV
CL = 1.1µF
CIN = 0.1µF
–10
–20
–30
–40
–50
–60
–70
–80
–90
CH1 RMS = 3.14µV
10
100
1k
10k
100k
FREQUENCY (Hz)
Figure 15. ADR3425 Output Voltage Noise (0.1 Hz to 10 Hz)
Figure 18. ADR3425 Ripple Rejection Ratio vs. Frequency
CIN = CL = 0.1µF
RL = ∞
1
VIN = 2V/DIV
1
100µV/DIV
TIME = 200µs/DIV
08440-030
08440-029
TIME = 1s/DIV
CH1 pk-pk = 300µV
2
VOUT = 1V/DIV
CH1 RMS = 42.0µV
Figure 16. ADR3425 Output Voltage Noise (10 Hz to 10 kHz)
Figure 19. ADR3425 Start-Up Response
12
ENABLE
8
6
1
4
VOUT = 1V/DIV
TIME = 200µs/DIV
2
2
1
10
100
1k
FREQUENCY (Hz)
10k
08440-031
0
0.1
VENABLE = 1V/DIV
VIN = 3.0v
CIN = CL = 0.1µF
RL = ∞
08440-023
NOISE DENSITY (µVp-p /√Hz)
10
Figure 17. ADR3425 Output Noise Spectral Density
Figure 20. ADR3425 Restart Response from Shutdown
Rev. B | Page 14 of 24
08440-025
RIPPLE REJECTION RATIO (dB VOUT/VIN)
0
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
1
08440-032
10µV/DIV
CH1 pk-pk = 33.4µV
CL = 1.1µF
CIN = 0.1µF
–10
–20
–30
–40
–50
–60
–70
–80
–90
CH1 RMS = 5.68µV
10
100
1k
10k
100k
FREQUENCY (Hz)
Figure 21. ADR3450 Output Voltage Noise (0.1 Hz to 10 Hz)
Figure 24. ADR3450 Ripple Rejection Ratio vs. Frequency
CIN = 0µF
CL = 0.1µF
RL = ∞
VIN
2V/DIV
1
1
VOUT
2V/DIV
100µV/DIV
08440-034
08440-033
CH1 pk-pk = 446µV
TIME = 200µs/DIV
2
CH1 RMS = 60.3µV
Figure 22. ADR3450 Output Voltage Noise (10 Hz to 10 kHz)
Figure 25. ADR3450 Start-Up Response
12
ENABLE
8
1
VENABLE = 2V/DIV
VIN = 5.5V
CIN = CL = 0.1µF
RL = ∞
6
VOUT = 2V/DIV
4
TIME = 200µs/DIV
2
1
10
100
1k
FREQUENCY (Hz)
10k
08440-035
0
0.1
2
08440-024
NOISE DENSITY (µVp-p/√Hz)
10
Figure 23. ADR3450 Output Noise Spectral Density
Figure 26. ADR3450 Restart Response from Shutdown
Rev. B | Page 15 of 24
08440-026
RIPPLE REJECTION RATIO (dB VOUT/VIN)
0
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
ENABLE
1V/DIV
ENABLE
2V/DIV
CIN = CL = 0.1µF
VIN = 5V
RL = 1kΩ
CIN = CL = 0.1µF
VIN = 3V
RL = 1kΩ
VOUT = 1V/DIV
2
08440-036
2
TIME = 200µs/DIV
VOUT = 2V/DIV
Figure 27. ADR3425 Shutdown Response
TIME = 200µs/DIV
Figure 30. ADR3450 Shutdown Response
VIN = 100mV/DIV
3.2V
5.5V
CIN = CL = 0.1µF
2.7V
500mV/DIV
08440-039
1
1
1
CIN = CL = 0.1µF
5.2V
2
VOUT = 10mV/DIV
2
TIME = 1ms/DIV
1
TIME = 1ms/DIV
Figure 31. ADR3450 Line Transient Response
Figure 28. ADR3425 Line Transient Response
IL
SOURCING
IL
08440-040
08440-037
VOUT = 5mV/DIV
+10mA
+10mA
SOURCING
SINKING
SINKING
–3mA
SINKING
SINKING
–3mA
CIN = 0.1µF
CL = 0.1µF
RL = 500Ω
CIN = 0.1µF
CL = 0.1µF
RL = 250Ω
5.0V
2.5V
08440-038
TIME = 1ms/DIV
TIME = 1ms/DIV
Figure 29. ADR3425 Load Transient Response
Figure 32. ADR3450 Load Transient Response
Rev. B | Page 16 of 24
08440-041
VOUT = 20mV/DIV
VOUT = 20mV/DIV
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
7
100
VIN = 5.5 V
90
6
NUMBER OF DEVICES
SUPPLY CURRENT (µA)
80
70
60
50
40
30
5
4
3
2
20
–10
5
20
35
50
65
80
95
110
0
125
TEMPERATURE (°C)
08440-043
–25
–0.050
–0.045
–0.040
–0.035
–0.030
–0.025
–0.020
–0.015
–0.010
–0.005
0
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
0.050
0.055
0
–40
1
08440-042
10
RELATIVE SHIFT IN VOUT (%)
Figure 36. Output Voltage Drift Distribution After Reflow (SHR Drift)
Figure 33. Supply Current vs. Temperature
2.0
8
1.6
7
6
1.4
NUMBER OF DEVICES
1.2
1.0
0.8
0.6
3
40
20
30
10
–10
0
–20
ENABLE VOLTAGE (% of VIN)
0
–40
–30
100
–50
90
–60
80
–70
70
–80
60
–90
50
–110
40
–100
30
–120
20
–150
10
08440-008
0
08440-044
1
0.2
OUTPUT VOLTAGE HYSTERESIS (ppm)
Figure 37. ADR3450 Thermally Induced Output Voltage Hysteresis Distribution
Figure 34. Supply Current vs. ENABLE Pin Voltage
80
CL = 0.1µF
CL = 1.1µF
1
0.1
40
20
0
–20
–40
–60
–80
0.1
1
10
100
1k
FREQUENCY (Hz)
10k
08440-027
0.01
0.01
60
Figure 35. ADR3450 Output Impedance vs. Frequency
08440-045
LONG-TERM OUTPUT VOLTAGE DRIFT (ppm)
10
OUTPUT IMPEDANCE (Ω)
4
2
0.4
0
5
–140
–130
SUPPLY CURRENT (mA)
TA = +25°C → +150°C → –50°C → +25°C
–40°C
+25°C
+125°C
1.8
0
200
400
600
800
1000
ELAPSED TIME (Hours)
Figure 38. ADR3450 Typical Long-Term Output Voltage Drift
(Four Devices, 1000 Hours)
Rev. B | Page 17 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
TERMINOLOGY
ΔVOUT _ HYS = VOUT (25°C ) − VOUT _ TC [V]
Dropout Voltage (VDO)
Dropout voltage, sometimes referred to as supply voltage
headroom or supply-output voltage differential, is defined as
the minimum voltage differential between the input and output
such that the output voltage is maintained to within 0.1%
accuracy.
ΔVOUT _ HYS =
Because the dropout voltage depends upon the current passing
through the device, it is always specified for a given load current.
In series-mode devices, dropout voltage typically increases
proportionally to load current (see Figure 8 and Figure 14).
Temperature Coefficient (TCVOUT)
The temperature coefficient relates the change in output voltage
to the change in ambient temperature of the device, as normalized
by the output voltage at 25°C. This parameter is expressed in
ppm/°C and can be determined by the following equation:
max{VOUT (T1 , T2 , T3 )} − min{VOUT (T1 , T2 , T3 )}
VOUT (T2 ) × (T3 − T1 )
VOUT (25°C )
× 10 6 [ppm]
where:
VOUT(25°C) is the output voltage at 25°C.
VOUT_TC is the output voltage after temperature cycling.
VDO = (VIN − VOUT)min | IL = constant
TCVOUT =
VOUT (25°C ) − VOUT _ TC
Long-Term Stability (ΔVOUT_LTD)
Long-term stability refers to the shift in output voltage at 50°C
after 1000 hours of operation in a 50°C environment. Ambient
temperature is kept at 50°C to ensure that the temperature
chamber does not switch randomly between heating and cooling,
which can cause instability over the 1000 hour measurement.
This is also expressed as either a shift in voltage or a difference
in ppm from the nominal output.
ΔVOUT _ LTD = VOUT (t 1 ) − VOUT (t 0 ) [V]
×
10 6 [ ppm / °C]
(1)
where:
VOUT(T) is the output voltage at Temperature T.
T1 = −40°C.
T2 = +25°C.
T3 = +125°C.
ΔVOUT _ LTD =
VOUT (t 1 ) − VOUT (t 0 )
VOUT (t 0 )
× 10 6 [ppm]
where:
VOUT(t0) is the VOUT at 50°C at Time 0.
VOUT(t1) is the VOUT at 50°C after 1000 hours of operation
at 50°C.
Line Regulation
Line regulation refers to the change in output voltage in response
to a given change in input voltage and is expressed in percent
per volt, ppm per volt, or μV per volt change in input voltage.
This parameter accounts for the effects of self-heating.
This three-point method ensures that TCVOUT accurately
portrays the maximum difference between any of the three
temperatures at which the output voltage of the part is
measured.
The TCVOUT for the ADR3412/ADR3425/ADR3430/ADR3433/
ADR3440/ADR3450 is guaranteed via statistical means. This is
accomplished by recording output voltage data for a large
number of units over temperature, computing TCVOUT for each
individual device via Equation 1, then defining the maximum
TCVOUT limits as the mean TCVOUT for all devices extended by
six standard deviations (6σ).
Thermally Induced Output Voltage Hysteresis (ΔVOUT_HYS)
Thermally induced output voltage hysteresis represents the
change in output voltage after the device is exposed to a
specified temperature cycle. This is expressed as either a shift in
voltage or a difference in ppm from the nominal output.
Load Regulation
Load regulation refers to the change in output voltage in
response to a given change in load current and is expressed in
μV per mA, ppm per mA, or ohms of dc output resistance. This
parameter accounts for the effects of self-heating.
Solder Heat Resistance (SHR) Drift
SHR drift refers to the permanent shift in output voltage
induced by exposure to reflow soldering, expressed in units of
ppm. This is caused by changes in the stress exhibited upon the
die by the package materials when exposed to high temperatures. This effect is more pronounced in lead-free soldering
processes due to higher reflow temperatures.
Rev. B | Page 18 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
THEORY OF OPERATION
VIN
ENABLE
BAND GAP
VOLTAGE
REFERENCE
LONG-TERM STABILITY
VBG
VOUT FORCE
VOUT SENSE
RFB1
GND FORCE
GND SENSE
08440-046
RFB2
Figure 39. Block Diagram
The ADR3412/ADR3425/ADR3430/ADR3433/ADR3440/
ADR3450 use a patented voltage reference architecture to
achieve high accuracy, low temperature coefficient (TC), and
low noise in a CMOS process. Like all band gap references, the
references combine two voltages of opposite TCs to create an
output voltage that is nearly independent of ambient temperature. However, unlike traditional band gap voltage references, the
temperature-independent voltage of the references are arranged
to be the base-emitter voltage, VBE, of a bipolar transistor at
room temperature rather than the VBE extrapolated to 0 K (the
VBE of bipolar transistor at 0 K is approximately VG0, the band
gap voltage of silicon). A corresponding positive-TC voltage is
then added to the VBE voltage to compensate for its negative TC.
The key benefit of this technique is that the trimming of the
initial accuracy and TC can be performed without interfering
with one another, thereby increasing overall accuracy across
temperature. Curvature correction techniques further reduce
the temperature variation.
The band gap voltage (VBG) is then buffered and amplified to
produce stable output voltages of 2.5 V and 5.0 V. The output
buffer can source up to 10 mA and sink up to −3 mA of load
current.
The ADR34xx family leverages Analog Devices patented
DigiTrim technology to achieve high initial accuracy and low
TC, and precision layout techniques lead to very low long-term
drift and thermal hysteresis.
One of the key parameters of the ADR34xx references is longterm stability. Regardless of output voltage, internal testing
during development showed a typical drift of approximately
30 ppm after 1000 hours of continuous, nonloaded operation
in a 50°C environment.
It is important to understand that long-term stability is not
guaranteed by design and that the output from the device may
shift beyond the typical 30 ppm specification at any time,
especially during the first 200 hours of operation. For systems
that require highly stable output voltages over long periods of
time, the designer should consider burning in the devices prior
to use to minimize the amount of output drift exhibited by the
reference over time. See the AN-713 Application Note, The
Effect of Long-Term Drift on Voltage References, at www.analog.com
for more information regarding the effects of long-term drift
and how it can be minimized.
POWER DISSIPATION
The ADR34xx voltage references are capable of sourcing up to
10 mA of load current at room temperature across the rated
input voltage range. However, when used in applications subject
to high ambient temperatures, the input voltage and load current should be carefully monitored to ensure that the device
does not exceeded its maximum power dissipation rating. The
maximum power dissipation of the device can be calculated via
the following equation:
PD =
TJ − TA
θ JA
[W ]
where:
PD is the device power dissipation.
TJ is the device junction temperature.
TA is the ambient temperature.
θJA is the package (junction-to-air) thermal resistance.
Because of this relationship, acceptable load current in high
temperature conditions may be less than the maximum currentsourcing capability of the device. In no case should the part be
operated outside of its maximum power rating because doing so
can result in premature failure or permanent damage to the device.
Rev. B | Page 19 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
APPLICATIONS INFORMATION
BASIC VOLTAGE REFERENCE CONNECTION
1µF
0.1µF
4
VIN
VOUT FORCE 6
3
ENABLE
VOUT SENSE 5
ADR34xx
VOUT
2.5V
0.1µF
08440-047
GND SENSE 2
GND FORCE 1
voltages can be sensed accurately. These voltages are fed back
into the internal amplifier and used to automatically correct for
the voltage drop across the current-carrying output and ground
lines, resulting in a highly accurate output voltage across the
load. To achieve the best performance, the sense connections
should be connected directly to the point in the load where the
output voltage should be the most accurate. See Figure 41 for an
example application.
OUTPUT CAPACITOR(S) SHOULD
BE MOUNTED AS CLOSE
TO VOUT FORCE PIN AS POSSIBLE.
Figure 40. Basic Reference Connection
The circuit shown in Figure 40 illustrates the basic configuration
for the ADR34xx references. Bypass capacitors should be
connected according to the following guidelines.
0.1µF
VIN
INPUT AND OUTPUT CAPACITORS
A 1 μF to 10 μF electrolytic or ceramic capacitor can be
connected to the input to improve transient response in
applications where the supply voltage may fluctuate. An
additional 0.1 μF ceramic capacitor should be connected
in parallel to reduce high frequency supply noise.
1µF
0.1µF
4 V
IN
VOUT FORCE 6
3 ENABLE
VOUT SENSE 5
ADR34xx
LOAD
SENSE CONNECTIONS
SHOULD CONNECT AS
CLOSE TO LOAD
DEVICE AS POSSIBLE.
GND SENSE 2
GND FORCE 1
A ceramic capacitor of at least a 0.1 μF must be connected to
the output to improve stability and help filter out high frequency noise. An additional 1 μF to 10 μF electrolytic or
ceramic capacitor can be added in parallel to improve transient
performance in response to sudden changes in load current;
however, the designer should keep in mind that doing so
increases the turn-on time of the device.
08440-048
VIN
2.7V TO
5.5V
Figure 41. Application Showing Kelvin Connection
It is always advantageous to use Kelvin connections whenever
possible. However, in applications where the IR drop is negligible or an extra set of traces cannot be routed to the load, the
force and sense pins for both VOUT and GND can simply be tied
together, and the device can be used in the same fashion as a
normal 3-terminal reference (as shown in Figure 40).
Best performance and stability is attained with low ESR (for
example, less than 1 Ω), low inductance ceramic chip-type
output capacitors (X5R, X7R, or similar). If using an electrolytic
capacitor on the output, a 0.1 μF ceramic capacitor should be
placed in parallel to reduce overall ESR on the output.
VIN SLEW RATE CONSIDERATIONS
4-WIRE KELVIN CONNECTIONS
To avoid such conditions, ensure that the input voltage waveform has both a rising and falling slew rate of at least 0.1 V/ms.
Current flowing through a PCB trace produces an IR voltage
drop, and with longer traces, this drop can reach several
millivolts or more, introducing a considerable error into the
output voltage of the reference. A 1 inch long, 5 millimeter wide
trace of 1 ounce copper has a resistance of approximately
100 mΩ at room temperature; at a load current of 10 mA, this
can introduce a full millivolt of error. In an ideal board layout,
the reference should be mounted as close to the load as possible
to minimize the length of the output traces, and, therefore, the
error introduced by voltage drop. However, in applications
where this is not possible or convenient, force and sense
connections (sometimes referred to as Kelvin sensing
connections) are provided as a means of minimizing the IR
drop and improving accuracy.
Kelvin connections work by providing a set of high impedance
voltage-sensing lines to the output and ground nodes. Because
very little current flows through these connections, the IR drop
across their traces is negligible, and the output and ground
In applications with slow-rising input voltage signals, the reference exhibits overshoot or other transient anomalies that appear
on the output. These phenomena also appear during shutdown
as the internal circuitry loses power.
SHUTDOWN/ENABLE FEATURE
The ADR34xx references can be switched to a low power shutdown mode when a voltage of 0.7 V or lower is input to the
ENABLE pin. Likewise, the reference becomes operational for
ENABLE voltages of 0.85 × VIN or higher. During shutdown, the
supply current drops to less than 5 μA, useful in applications that
are sensitive to power consumption.
If using the shutdown feature, ensure that the ENABLE pin
voltage does not fall between 0.7 V and 0.85 × VIN because this
causes a large increase in the supply current of the device and
may keep the reference from starting up correctly (see Figure 34).
If not using the shutdown feature, however, the ENABLE pin
can simply be tied to the VIN pin, and the reference remains
operational continuously.
Rev. B | Page 20 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
VIN
4 V
IN
Negative Reference
+5V
VOUT FORCE 6
R1
10kΩ
3 ENABLE V
5
OUT SENSE
Figure 42 shows how to connect the ADR3450 and a standard
CMOS op amp, such as the AD8663, to provide a negative
reference voltage. This configuration provides two main
advantages: first, it only requires two devices and, therefore,
does not require excessive board space; second, and more
importantly, it does not require any external resistors, meaning
that the performance of this circuit does not rely on choosing
expensive parts with low temperature coefficients to ensure
accuracy.
1µF
0.1µF
ADR3450
0.1µF
R2
10kΩ
GND SENSE 2
GND FORCE 1
+15V
–5V
ADA4000-1
R3
5kΩ
08440-050
SAMPLE APPLICATIONS
–15V
+VDD
Figure 43. ADR3450 Bipolar Output Reference
4
3
VIN
VOUT FORCE
AD8663
6
ENABLE VOUT SENSE 5
ADR3450
GND SENSE 2
–5V
0.1µF
–VDD
GND FORCE 1
0.1µF
Figure 42. ADR3450 Negative Reference
In this configuration, the VOUT pins of the reference sit at virtual
ground, and the negative reference voltage and load current are
taken directly from the output of the operational amplifier. Note
that in applications where the negative supply voltage is close to
the reference output voltage, a dual-supply, low offset, rail-torail output amplifier must be used to ensure an accurate output
voltage. The operational amplifier must also be able to source or
sink an appropriate amount of current for the application.
Boosted Output Current Reference
Figure 44 shows a configuration for obtaining higher current
drive capability from the ADR34xx references without
sacrificing accuracy. The op amp regulates the current flow
through the MOSFET until VOUT equals the output voltage of
the reference; current is then drawn directly from VIN instead of
from the reference itself, allowing increased current drive
capability.
VIN
+16V
U6
4
VIN
VOUT FORCE 6
3
ENABLE
VOUT SENSE 5
1µF 0.1µF
ADR34xx
R1
100Ω
2N7002
AD8663
VOUT
0.1µF
RL
200Ω
Bipolar Output Reference
Figure 43 shows a bipolar reference configuration. By connecting
the output of the ADR3450 to the inverting terminal of an
operational amplifier, it is possible to obtain both positive and
negative reference voltages. R1 and R2 must be matched as
closely as possible to ensure minimal difference between the
negative and positive outputs. Resistors with low temperature
coefficients must also be used if the circuit is used in environments
with large temperature swings; otherwise, a voltage difference
develops between the two outputs as the ambient temperature
changes.
CL
0.1µF
GND SENSE 2
GND FORCE 1
08440-051
0.1µF
08440-049
1µF
Figure 44. Boosted Output Current Reference
Because the current-sourcing capability of this circuit depends
only on the ID rating of the MOSFET, the output drive capability
can be adjusted to the application simply by choosing an
appropriate MOSFET. In all cases, the VOUT SENSE pin should
be tied directly to the load device to maintain maximum output
voltage accuracy.
Rev. B | Page 21 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
OUTLINE DIMENSIONS
3.00
2.90
2.80
1.70
1.60
1.50
6
5
4
1
2
3
PIN 1
INDICATOR
3.00
2.80
2.60
0.95 BSC
1.90
BSC
0.15 MAX
0.05 MIN
1.45 MAX
0.95 MIN
0.50 MAX
0.30 MIN
0.20 MAX
0.08 MIN
SEATING
PLANE
10°
4°
0°
0.60
BSC
COMPLIANT TO JEDEC STANDARDS MO-178-AB
0.55
0.45
0.35
121608-A
1.30
1.15
0.90
Figure 45. 6-Lead Small Outline Transistor Package (SOT-23)
(RJ-6)
Dimensions shown in millimeters
ORDERING GUIDE
Model 1
ADR3412ARJZ-R2
ADR3412ARJZ-R7
ADR3420ARJZ-R2
ADR3420ARJZ-R7
ADR3425ARJZ-R2
ADR3425ARJZ-R7
ADR3430ARJZ-R2
ADR3430ARJZ-R7
ADR3433ARJZ-R2
ADR3433ARJZ-R7
ADR3440ARJZ-R2
ADR3440ARJZ-R7
ADR3450ARJZ-R2
ADR3450ARJZ-R7
1
Output Voltage (V)
1.200
1.200
2.048
2.048
2.500
2.500
3.000
3.000
3.300
3.300
4.096
4.096
5.000
5.000
Temperature Range
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
Package Description
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
6-Lead SOT-23
Z = RoHS Compliant Part.
Rev. B | Page 22 of 24
Package Option
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
RJ-6
Ordering
Quantity
250
3,000
250
3,000
250
3,000
250
3,000
250
3,000
250
3,000
250
3,000
Branding
R2R
R2R
R2V
R2V
R2X
R2X
R2Z
R2Z
R31
R31
R33
R33
R34
R34
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
NOTES
Rev. B | Page 23 of 24
ADR3412/ADR3420/ADR3425/ADR3430/ADR3433/ADR3440/ADR3450
NOTES
©2010 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D08440-0-6/10(B)
Rev. B | Page 24 of 24