ADR441A [ADI]
Ultralow Noise, LDO XFET Voltage References with Current Sink and Source; 超低噪声， LDO XFET基准电压与电流吸收和源
| 型号： | ADR441A |
| 厂家： | 
ADI |
| 描述： | Ultralow Noise, LDO XFET Voltage References with Current Sink and Source |
| 文件： | 总20页 (文件大小：568K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Ultralow Noise, LDO XFET® Voltage
References with Current Sink and Source
ADR440/ADR441/ADR443/ADR444/ADR445
FEATURES
PIN CONFIGURATIONS
Ultralow noise (0.1 Hz to 10 Hz)
ADR440: 1 μV p-p
ADR441: 1.2 μV p-p
ADR443: 1.4 μV p-p
ADR444: 1.8 μV p-p
ADR445: 2.25 μV p-p
Superb temperature coefficient
A Grade: 10 ppm/°C
ADR440/
TP
1
2
3
4
8
7
6
5
TP
ADR441/
ADR443/
ADR444/
ADR445
V
NC
IN
NC
V
OUT
TOP VIEW
(Not to Scale)
GND
TRIM
NOTES
1. NC = NO CONNECT
2. TP = TEST PIN (DO NOT CONNECT)
Figure 1. 8-Lead SOIC_N (R-Suffix)
B Grade: 3 ppm/°C
Low dropout operation: 500 mV
Input range: (VOUT + 500 mV) to 18 V
High output source and sink current: +10 mA and −5 mA
Wide temperature range: −40°C to +125°C
ADR440/
TP
1
2
3
4
8
7
6
5
TP
ADR441/
ADR443/
ADR444/
ADR445
V
NC
IN
NC
V
OUT
TOP VIEW
(Not to Scale)
APPLICATIONS
GND
TRIM
Precision data acquisition systems
High resolution data converters
Battery-powered instrumentations
Portable medical instruments
Industrial process control systems
Precision instruments
NOTES
1. NC = NO CONNECT
2. TP = TEST PIN (DO NOT CONNECT)
Figure 2. 8-Lead MSOP (RM-Suffix)
Optical control circuits
GENERAL DESCRIPTION
Offered in two electrical grades, the ADR44x family is avail-
able in 8-lead MSOP and narrow SOIC packages. All versions
are specified over the extended industrial temperature range of
−40°C to +125°C.
The ADR44x series is a family of XFET voltage references
featuring ultralow noise, high accuracy, and low temperature
drift performance. Using Analog Devices, Inc., patented
temperature drift curvature correction and XFET (eXtra
implanted junction FET) technology, voltage change vs.
temperature nonlinearity in the ADR44x is greatly minimized.
Table 1. Selection Guide
Output
Voltage
(V)
Initial
Accuracy,
(mV)
Temperature
Coefficient
(ppm/°C)
The XFET references offer better noise performance than
buried Zener references, and XFET references operate off
low supply voltage headroom (0.5 V). This combination of
features makes the ADR44x family ideally suited for precision
signal conversion applications in high-end data acquisition
systems, optical networks, and medical applications.
Model
ADR440A 2.048
ADR440B 2.048
ADR441A 2.500
ADR441B 2.500
ADR443A 3.000
ADR443B 3.000
ADR444A 4.096
ADR444B 4.096
ADR445A 5.000
ADR445B 5.000
3
1
3
1
4
1.2
5
1.6
6
2
10
3
10
3
10
3
10
3
The ADR44x family has the capability to source up to 10 mA of
output current and sink up to 5 mA. It also comes with a trim
terminal to adjust the output voltage over a 0.5% range without
compromising performance.
10
3
Rev. A
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 registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2006 Analog Devices, Inc. All rights reserved.
ADR440/ADR441/ADR443/ADR444/ADR445
TABLE OF CONTENTS
Theory of Operation ...................................................................... 14
Power Dissipation Considerations........................................... 14
Basic Voltage Reference Connections ..................................... 14
Noise Performance..................................................................... 14
Turn-On Time ............................................................................ 14
Applications..................................................................................... 15
Output Adjustment .................................................................... 15
Bipolar Outputs .......................................................................... 15
Negative Reference..................................................................... 15
Programmable Voltage Source ................................................. 16
Programmable Current Source ................................................ 16
High Voltage Floating Current Source.................................... 16
Precision Output Regulator (Boosted Reference).................. 17
Outline Dimensions....................................................................... 18
Ordering Guide .......................................................................... 19
Features .............................................................................................. 1
Applications....................................................................................... 1
Pin Configurations ........................................................................... 1
General Description......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
ADR440 Electrical Characteristics............................................. 3
ADR441 Electrical Characteristics............................................. 4
ADR443 Electrical Characteristics............................................. 5
ADR444 Electrical Characteristics............................................. 6
ADR445 Electrical Characteristics............................................. 7
Absolute Maximum Ratings............................................................ 8
Thermal Resistance ...................................................................... 8
ESD Caution.................................................................................. 8
Typical Performance Characteristics ............................................. 9
REVISION HISTORY
9/06—Rev. 0 to Rev. A
Updated Format..................................................................Universal
Changes to Features.......................................................................... 1
Changes to Pin Configurations....................................................... 1
Changes to the Specifications Section ........................................... 3
Changes to Figure 4 and Figure 5................................................... 9
Inserted Figure 6 and Figure 7........................................................ 9
Changes to Figure 15...................................................................... 11
Changes to the Power Dissipation Considerations Section...... 14
Changes to Figure 35 and Figure 36............................................. 15
Changes to Figure 38 and Table 9................................................. 16
Updated Outline Dimensions....................................................... 18
Changes to Ordering Guide .......................................................... 19
10/05—Revision 0: Initial Version
Rev. A | Page 2 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
SPECIFICATIONS
ADR440 ELECTRICAL CHARACTERISTICS
VIN = 3 V to 18 V, TA = 25°C, CIN = COUT = 0.1 μF, unless otherwise noted.
Table 2.
Parameter
OUTPUT VOLTAGE
A Grade
Symbol
Conditions
Min
Typ
Max
Unit
VO
2.045
2.047
2.048
2.048
2.051
2.049
V
V
B Grade
INITIAL ACCURACY
A Grade
VOERR
3
0.15
1
mV
%
mV
%
B Grade
0.05
TEMPERATURE DRIFT
A Grade
B Grade
TCVO
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
2
1
10
3
ppm/°C
ppm/°C
ppm/V
LINE REGULATION
LOAD REGULATION
ΔVO/ΔVIN
−20
−50
−50
+10
+20
ΔVO/ΔILOAD
ILOAD = 0 mA to 10 mA, VIN = 3.5 V,
−40°C < TA < +125°C
ILOAD = 0 mA to −5 mA, VIN = 3.5 V,
−40°C < TA < +125°C
+50
ppm/mA
ΔVO/ΔILOAD
+50
3.75
ppm/mA
mA
QUIESCENT CURRENT
IIN
No load, −40°C < TA < +125°C
0.1 Hz to 10 Hz
3
VOLTAGE NOISE
eN p-p
eN
1
μV p-p
nV/√Hz
μs
VOLTAGE NOISE DENSITY
TURN-ON SETTLING TIME
LONG-TERM STABILITY1
1 kHz
45
10
50
70
−75
27
tR
VO
1000 hours
fIN = 10 kHz
ppm
ppm
dB
OUTPUT VOLTAGE HYSTERESIS
RIPPLE REJECTION RATIO
SHORT CIRCUIT TO GND
SUPPLY VOLTAGE OPERATING RANGE
SUPPLY VOLTAGE HEADROOM
VO_HYS
RRR
ISC
mA
VIN
3
18
V
VIN − VO
500
mV
1 The long-term stability specification is noncumulative. The drift in the subsequent 1000-hour period is significantly lower than in the first 1000-hour period.
Rev. A | Page 3 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
ADR441 ELECTRICAL CHARACTERISTICS
VIN = 3 V to 18 V, TA = 25°C, CIN = COUT = 0.1 μF, unless otherwise noted.
Table 3.
Parameter
OUTPUT VOLTAGE
A Grade
Symbol
Conditions
Min
Typ
Max
Unit
VO
2.497
2.499
2.500
2.500
2.503
2.501
V
V
B Grade
INITIAL ACCURACY
A Grade
VOERR
3
0.12
1
mV
%
mV
%
B Grade
0.04
TEMPERATURE DRIFT
A Grade
B Grade
TCVO
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
2
1
10
3
ppm/°C
ppm/°C
ppm/V
LINE REGULATION
LOAD REGULATION
ΔVO/ΔVIN
10
20
ΔVO/ΔILOAD
ILOAD = 0 mA to 10 mA, VIN = 4 V,
−40°C < TA < +125°C
ILOAD = 0 mA to −5 mA, VIN = 4 V,
−40°C < TA < +125°C
−50
−50
+50
ppm/mA
ΔVO/ΔILOAD
+50
3.75
ppm/mA
mA
QUIESCENT CURRENT
IIN
No load, −40°C < TA < +125°C
0.1 Hz to 10 Hz
3
VOLTAGE NOISE
eN p-p
eN
1.2
48
10
50
70
−75
27
μV p-p
nV/√Hz
μs
VOLTAGE NOISE DENSITY
TURN-ON SETTLING TIME
LONG-TERM STABILITY1
OUTPUT VOLTAGE HYSTERESIS
RIPPLE REJECTION RATIO
SHORT CIRCUIT TO GND
SUPPLY VOLTAGE OPERATING RANGE
SUPPLY VOLTAGE HEADROOM
1 kHz
tR
VO
1000 hours
fIN = 10 kHz
ppm
ppm
dB
VO_HYS
RRR
ISC
mA
VIN
3
18
V
VIN − VO
500
mV
1 The long-term stability specification is noncumulative. The drift in subsequent 1000-hour period is significantly lower than in the first 1000-hour period.
Rev. A | Page 4 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
ADR443 ELECTRICAL CHARACTERISTICS
VIN = 3.5 V to 18 V, TA = 25°C, CIN = COUT = 0.1 μF, unless otherwise noted.
Table 4.
Parameter
OUTPUT VOLTAGE
A Grade
Symbol
Conditions
Min
Typ
Max
Unit
VO
2.996
2.9988
3.000
3.000
3.004
3.0012
V
V
B Grade
INITIAL ACCURACY
A Grade
VOERR
4
mV
%
mV
%
0.13
1.2
0.04
B Grade
TEMPERATURE DRIFT
A Grade
B Grade
TCVO
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
2
1
10
3
ppm/°C
ppm/°C
ppm/V
LINE REGULATION
LOAD REGULATION
ΔVO/ΔVIN
10
20
ΔVO/ΔILOAD
ILOAD = 0 mA to 10 mA, VIN = 5 V,
−40°C < TA < +125°C
ILOAD = 0 mA to −5 mA, VIN = 5 V,
−40°C < TA < +125°C
−50
−50
+50
ppm/mA
ΔVO/ΔILOAD
+50
3.75
ppm/mA
mA
QUIESCENT CURRENT
IIN
No load, −40°C < TA < +125°C
0.1 Hz to 10 Hz
3
VOLTAGE NOISE
eN p-p
eN
1.4
57.6
10
μV p-p
nV/√Hz
μs
VOLTAGE NOISE DENSITY
TURN-ON SETTLING TIME
LONG-TERM STABILITY1
1 kHz
tR
VO
1000 hours
fIN = 10 kHz
50
ppm
ppm
dB
OUTPUT VOLTAGE HYSTERESIS
RIPPLE REJECTION RATIO
SHORT CIRCUIT TO GND
SUPPLY VOLTAGE OPERATING RANGE
SUPPLY VOLTAGE HEADROOM
VO_HYS
RRR
ISC
70
−75
27
mA
VIN
3.5
18
V
VIN − VO
500
mV
1 The long-term stability specification is noncumulative. The drift in the subsequent 1000-hour period is significantly lower than in the first 1000-hour period.
Rev. A | Page 5 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
ADR444 ELECTRICAL CHARACTERISTICS
VIN = 4.6 V to 18 V, TA = 25°C, CIN = COUT = 0.1 μF, unless otherwise noted.
Table 5.
Parameter
OUTPUT VOLTAGE
A Grade
Symbol
Conditions
Min
Typ
Max
Unit
VO
4.091
4.0944
4.096
4.096
4.101
4.0976
V
V
B Grade
INITIAL ACCURACY
A Grade
VOERR
5
mV
%
mV
%
0.13
1.6
0.04
B Grade
TEMPERATURE DRIFT
A Grade
B Grade
TCVO
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
2
1
10
3
ppm/°C
ppm/°C
ppm/V
LINE REGULATION
LOAD REGULATION
ΔVO/ΔVIN
10
20
ΔVO/ΔILOAD
ILOAD = 0 mA to 10 mA, VIN = 5.5 V,
−40°C < TA < +125°C
ILOAD = 0 mA to −5 mA, VIN = 5.5 V,
−40°C < TA < +125°C
−50
−50
+50
ppm/mA
ΔVO/ΔILOAD
+50
3.75
ppm/mA
mA
QUIESCENT CURRENT
IIN
No load, −40°C < TA < +125°C
0.1 Hz to 10 Hz
3
VOLTAGE NOISE
eN p-p
eN
1.8
78.6
10
μV p-p
nV/√Hz
μs
VOLTAGE NOISE DENSITY
TURN-ON SETTLING TIME
LONG-TERM STABILITY1
1 kHz
tR
VO
1000 hours
fIN = 10 kHz
50
ppm
ppm
dB
OUTPUT VOLTAGE HYSTERESIS
RIPPLE REJECTION RATIO
SHORT CIRCUIT TO GND
SUPPLY VOLTAGE OPERATING RANGE
SUPPLY VOLTAGE HEADROOM
VO_HYS
RRR
ISC
70
−75
27
mA
VIN
4.6
18
V
VIN − VO
500
mV
1 The long-term stability specification is noncumulative. The drift in the subsequent 1000-hour period is significantly lower than in the first 1000-hour period.
Rev. A | Page 6 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
ADR445 ELECTRICAL CHARACTERISTICS
VIN = 5.5 V to 18 V, TA = 25°C, CIN = COUT = 0.1 μF, unless otherwise noted.
Table 6.
Parameter
OUTPUT VOLTAGE
A Grade
Symbol
Conditions
Min
Typ
Max
Unit
VO
4.994
4.998
5.000
5.000
5.006
5.002
V
V
B Grade
INITIAL ACCURACY
A Grade
VOERR
6
0.12
2
mV
%
mV
%
B Grade
0.04
TEMPERATURE DRIFT
A Grade
B Grade
TCVO
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
2
1
10
3
ppm/°C
ppm/°C
ppm/V
LINE REGULATION
LOAD REGULATION
ΔVO/ΔVIN
10
20
ΔVO/ΔILOAD
ILOAD = 0 mA to 10 mA, VIN = 6.5 V,
−40°C < TA < +125°C
ILOAD = 0 mA to −5 mA, VIN = 6.5 V,
−40°C < TA < +125°C
−50
−50
+50
ppm/mA
ΔVO/ΔILOAD
+50
3.75
ppm/mA
mA
QUIESCENT CURRENT
IIN
No load, −40°C < TA < +125°C
0.1 Hz to 10 Hz
3
VOLTAGE NOISE
eN p-p
eN
2.25
90
10
50
70
–75
27
μV p-p
nV/√Hz
μs
VOLTAGE NOISE DENSITY
TURN-ON SETTLING TIME
LONG-TERM STABILITY1
1 kHz
tR
VO
1000 hours
fIN = 10 kHz
ppm
ppm
dB
OUTPUT VOLTAGE HYSTERESIS
RIPPLE REJECTION RATIO
SHORT CIRCUIT TO GND
SUPPLY VOLTAGE OPERATING RANGE
SUPPLY VOLTAGE HEADROOM
VO_HYS
RRR
ISC
mA
VIN
5.5
18
V
VIN − VO
500
mV
1 The long-term stability specification is noncumulative. The drift in the subsequent 1000-hour period is significantly lower than in the first 1000-hour period.
Rev. A | Page 7 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
TA = 25°C, unless otherwise noted.
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Table 7.
Parameter
Rating
Table 8. Thermal Resistance
Supply Voltage
20 V
Output Short-Circuit Duration to GND
Storage Temperature Range
Operating Temperature Range
Junction Temperature Range
Lead Temperature, Soldering (60 sec)
Indefinite
Package Type
θJA
θJC
Unit
°C/W
°C/W
−65°C to +125°C
−40°C to +125°C
−65°C to +150°C
300°C
8-Lead SOIC_N (R-Suffix)
8-Lead MSOP (RM-Suffix)
130
190
43
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. A | Page 8 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 7 V, TA = 25°C, CIN = COUT = 0.1 μF, unless otherwise noted.
2.051
2.5020
2.5015
2.5010
2.5005
2.5000
2.050
2.049
2.048
2.047
2.046
2.045
2.4995
2.4990
–40
–20
0
20
40
60
80
100
120
–40 –25 –10
5
20
35
50
65
80
95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 3. ADR441 Output Voltage vs. Temperature
Figure 6. ADR440 Output Voltage vs. Temperature
5.006
3.0020
3.0015
3.0010
3.0005
3.0000
2.9995
2.9990
5.004
5.002
UNIT 1
UNIT 2
5.000
4.998
4.996
4.994
UNIT 3
2.9985
2.9980
–40
–20
0
20
40
60
80
100
120
–40 –25 –10
5
20
35
50
65
80
95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 4. ADR443 Output Voltage vs. Temperature
Figure 7. ADR445 Output Voltage vs. Temperature
4.0980
4.0
3.5
3.0
4.0975
4.0970
4.0965
4.0960
4.0955
4.0950
UNIT 1
+125°C
+25°C
UNIT 2
UNIT 3
–40°C
2.5
2.0
4.0945
4.0940
–40 –25 –10
5
20
35
50
65
80
95 110 125
4
6
8
10
12
14
16
18
TEMPERATURE (°C)
INPUT VOLTAGE (V)
Figure 5. ADR444 Output Voltage vs. Temperature
Figure 8. ADR441 Supply Current vs. Input Voltage
Rev. A | Page 9 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
4.0
10
8
3.5
3.0
6
4
2.5
2.0
2
0
–40 –25 –10
5
20
35
50
65
80
95 110 125
–40 –25 –10
5
20
35
50
65
80
95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 9. ADR441 Supply Current vs. Temperature
Figure 12. ADR441 Line Regulation vs. Temperature
60
3.5
3.4
3.3
3.2
55
50
45
V
= 18V
IN
3.1
3.0
+125°C
I
= 0mA TO 10mA
LOAD
V
= 6V
IN
2.9
2.8
+25°C
–40°C
40
2.7
35
30
2.6
2.5
–40 –25 –10
5
20
35
50
65
80
95 110 125
5.3
7.3
9.3
11.3
13.3
15.3
17.3
19.3
TEMPERATURE (°C)
INPUT VOLTAGE (V)
Figure 13. ADR441 Load Regulation vs. Temperature
Figure 10. ADR445 Supply Current vs. Input Voltage
7
3.25
6
5
4
3.15
3.05
3
2
2.95
2.85
2.75
1
0
–40 –25 –10
5
20
35
50
65
80
95 110 125
–40 –25 –10
5
20
35
50
65
80
95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 14. ADR445 Line Regulation vs. Temperature
Figure 11. ADR445 Quiescent Current vs. Temperature
Rev. A | Page 10 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
50
40
30
1.0
0.9
0.8
I
= 0mA TO +10mA
LOAD
+125°C
0.7
0.6
0.5
20
10
V
= 6V
IN
0
+25°C
–10
0.4
0.3
0.2
–40°C
–20
–30
–40
–50
I
= 0mA TO –5mA
LOAD
0.1
0
–40 –25 –10
5
20
35
50
65
80
95 110 125
–5
0
5
10
TEMPERATURE (°C)
LOAD CURRENT (mA)
Figure 15. ADR445 Load Regulation vs. Temperature
Figure 18. ADR445 Minimum Input/Output
Differential Voltage vs. Load Current
0.7
0.5
NO LOAD
0.6
0.5
0.4
0.4
0.3
0.2
+125°C
+25°C
–40°C
0.3
0.2
0.1
0
0.1
0
–10
–5
0
5
10
–40 –25 –10
5
20
35
50
65
80
95 110 125
LOAD CURRENT (mA)
TEMPERATURE (°C)
Figure 16. ADR441 Minimum Input/Output
Differential Voltage vs. Load Current
Figure 19. ADR445 Minimum Headroom vs. Temperature
0.5
NO LOAD
C
, C = 0.1µF
OUT
IN
0.4
0.3
0.2
V
= 5V/DIV
IN
0.1
0
V
= 1V/DIV
OUT
TIME = 10µs/DIV
–40 –25 –10
5
20
35
50
65
80
95 110 125
TEMPERATURE (°C)
Figure 17. ADR441 Minimum Headroom vs. Temperature
Figure 20. ADR441 Turn-On Response
Rev. A | Page 11 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
C
, C
= 0.1µF
C
, C = 0.1µF
IN
OUT
IN OUT
LOAD OFF
LOAD ON
V
= 5V/DIV
IN
5mV/DIV
V
= 1V/DIV
OUT
TIME = 200µs/DIV
TIME = 200µs/DIV
Figure 24. ADR441 Load Transient Response
Figure 21. ADR441 Turn-Off Response
C
C
= 0.1µF
IN
C
C
= 0.1µF
IN
= 10µF
OUT
= 10µF
OUT
LOAD ON
LOAD OFF
V
= 5V/DIV
IN
5mV/DIV
V
= 1V/DIV
OUT
TIME = 200µs/DIV
TIME = 200µs/DIV
Figure 22. ADR441 Turn-On Response
Figure 25. ADR441 Load Transient Response
C
C
= 0.1µF
IN
= 10µF
OUT
2V/DIV
4V
1µV/DIV
CH1 p-p
1.18µV
2mV/DIV
TIME = 1s/DIV
TIME = 100µs/DIV
Figure 23. ADR441 Line Transient Response
Figure 26. ADR441 0.1 Hz to 10.0 Hz Voltage Noise
Rev. A | Page 12 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
16
14
12
10
8
50µV/DIV
6
CH1 p-p
49µV
4
2
0
TIME = 1s/DIV
DEVIATION (PPM)
Figure 30. ADR441 Typical Output Voltage Hysteresis
Figure 27. ADR441 10 Hz to 10 kHz Voltage Noise
10
9
8
7
ADR445
6
5
1µV/DIV
ADR443
CH1 p-p
2.24µV
4
3
2
ADR441
1
0
10
100
1k
10k
100k
TIME = 1s/DIV
FREQUENCY (Hz)
Figure 31. Output Impedance vs. Frequency
Figure 28. ADR445 0.1 Hz to 10.0 Hz Voltage Noise
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
50µV/DIV
CH1 p-p
66µV
100
1k
10k
100k
1M
TIME = 1s/DIV
FREQUENCY (Hz)
Figure 32. Ripple Rejection Ratio vs. Frequency
Figure 29. ADR445 10 Hz to 10 kHz Voltage Noise
Rev. A | Page 13 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
THEORY OF OPERATION
POWER DISSIPATION CONSIDERATIONS
The ADR44x series of references uses a new reference generation
technique known as XFET (eXtra implanted junction FET).
This technique yields a reference with low dropout, good
thermal hysteresis, and exceptionally low noise. The core of the
XFET reference consists of two junction field-effect transistors
(JFETs), one of which has an extra channel implant to raise its
pinch-off voltage. By running the two JFETs at the same drain
current, the difference in pinch-off voltage can be amplified
and used to form a highly stable voltage reference.
The ADR44x family of references is guaranteed to deliver load
currents to 10 mA with an input voltage that ranges from 3 V to
18 V. When these devices are used in applications at higher
currents, users should use the following equation to account for
the temperature effects of increases in power dissipation:
TJ =PD × θJA + TA
where:
(2)
TJ and TA are the junction and ambient temperatures,
respectively.
PD is the device power dissipation.
The intrinsic reference voltage is around 0.5 V with a negative
temperature coefficient of about –120 ppm/°C. This slope is
essentially constant to the dielectric constant of silicon, and it can
be closely compensated for by adding a correction term generated
in the same fashion as the proportional-to-temperature (PTAT)
term used to compensate band gap references. The advantage
of an XFET reference is its correction term, which is approx-
imately 20 times lower and requires less correction than that of a
band gap reference. Because most of the noise of a band gap
reference comes from the temperature compensation circuitry,
the XFET results in much lower noise.
θJA is the device package thermal resistance.
BASIC VOLTAGE REFERENCE CONNECTIONS
The ADR44x family requires a 0.1 μF capacitor on the input
and the output for stability. While not required for operation,
a 10 μF capacitor at the input can help with line voltage
transient performance.
ADR440/
ADR441/
ADR443/
ADR444/
ADR445
TP
1
2
3
4
8
7
6
5
TP
Figure 33 shows the basic topology of the ADR44x series. The
temperature correction term is provided by a current source
with a value designed to be proportional to absolute temperature.
The general equation is
V
IN
NC
+
V
OUT
10µF
0.1µF
NC
GND
TOP VIEW
(Not to Scale)
0.1µF
TRIM
NOTES
1. NC = NO CONNECT
2. TP = TEST PIN (DO NOT CONNECT)
VOUT = G ΔVP −R1× IPTAT
(1)
where:
Figure 34. Basic Voltage Reference Configuration
G is the gain of the reciprocal of the divider ratio.
ꢀVP is the difference in pinch-off voltage between the two JFETs.
NOISE PERFORMANCE
The noise generated by the ADR44x family of references is
typically less than 1.4 μV p-p over the 0.1 Hz to 10.0 Hz band
for ADR440, ADR441, and ADR443. Figure 26 shows the 0.1 Hz
to 10 Hz noise of the ADR441, which is only 1.2 μV p-p. The
noise measurement is made with a band-pass filter made of a
2pole high-pass filter with a corner frequency at 0.1 Hz and a
2pole low-pass filter with a corner frequency at 10.0 Hz.
I
PTAT is the positive temperature coefficient correction current.
ADR44x devices are created by on-chip adjustment of R2
and R3 to achieve the different voltage option at the
reference output.
V
IN
I
I
I
PTAT
1
1
TURN-ON TIME
V
ADR44x
OUT
Upon application of power (cold start), the time required for
the output voltage to reach its final value within a specified
error band is defined as the turn-on settling time. Two compo-
nents normally associated with this are the time for the active
circuits to settle and the time for the thermal gradients on the
chip to stabilize. Figure 20 and Figure 21 show the turn-on and
turn-off settling times for the ADR441.
R2
R3
*
ΔV
P
R1
*EXTRA CHANNEL IMPLANT
= G (ΔV – R1 × I
V
)
OUT
P
PTAT
GND
Figure 33. Simplified Schematic Device
Rev. A | Page 14 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
APPLICATIONS
OUTPUT ADJUSTMENT
+V
DD
The ADR44x family features a TRIM pin that allows the user to
adjust the output voltage of the part over a limited range. This
allows errors from the reference and overall system errors to be
trimmed out by connecting a potentiometer between the output
and the ground, with the wiper connected to the TRIM pin.
Figure 35 shows the optimal trim configuration. R1 allows fine
adjustment of the output and is not always required. RP should
be sufficiently large so that the maximum output current from
the ADR44x is not exceeded.
2
V
IN
ADR440/
ADR441/
ADR443/
ADR444/
ADR445
0.1µF
V
6
+5V
–5V
OUT
R1
10kΩ
R2
0.1µF
GND
4
10kΩ
+10V
0.1µF
R3
5kΩ
2
–10V
V
IN
V
Figure 36. ADR44x Bipolar Outputs
V
O
= ±0.5%
6
OUT
0.1µF
ADR440/
ADR441/
ADR443/
ADR444/
ADR445
NEGATIVE REFERENCE
Figure 37 shows how to connect the ADR44x and a standard
operational amplifier, such as the OP1177, to provide negative
voltage. This configuration provides two main advantages. First,
it only requires two devices; therefore, it does not require
excessive board space. Second, and more importantly, it does
not require any external resistors. This means the performance
of this circuit does not rely on choosing low temperature
coefficient resistors to ensure accuracy.
R
10kΩ
P
5
TRIM
GND
4
R1
100kΩ
R2
1kΩ
Figure 35. ADR44x Trim Function
Using the trim function has a negligible effect on the temperature
performance of the ADR44x. However, all resistors need to be
low temperature coefficient resistors, or errors can occur.
+V
DD
2
BIPOLAR OUTPUTS
V
IN
ADR440/
ADR441/
ADR443/
ADR444/
ADR445
By connecting the output of the ADR44x to the inverting
terminal of an operational amplifier, it is possible to obtain both
positive and negative reference voltages. Care must be taken
when choosing Resistor R1 and Resistor R2 (see Figure 36).
They must be matched as closely as possible to ensure minimal
differences between the negative and positive outputs. In
addition, care must be taken to ensure performance over
temperature. Use low temperature coefficient resistors if the
circuit is used over temperature; otherwise, differences exist
between the two outputs.
6
V
OUT
GND
4
–V
REF
–V
DD
Figure 37. ADR44x Negative Reference
VOUT is at virtual ground, and the negative reference is taken
directly from the output of the operational amplifier. If the
negative supply voltage is close to the reference output, the
operational amplifier must be dual supply and have low offset
and rail-to-rail capability.
Rev. A | Page 15 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
PROGRAMMABLE VOLTAGE SOURCE
PROGRAMMABLE CURRENT SOURCE
To obtain different voltages than those offered by the ADR44x,
some extra components are needed. In Figure 38, two
potentiometers are used to set the desired voltage, while the
buffering amplifier provides current drive. The potentiometer
connected between VOUT and GND, with its wiper connected to
the noninverting input of the operational amplifier, takes care of
coarse trim. The second potentiometer, with its wiper
It is possible to build a programmable current source using a
setup similar to the programmable voltage source, as shown in
Figure 39. The constant voltage on the gate of the transistor sets
the current through the load. Varying the voltage on the gate
changes the current. This circuit does not require a dual digital
potentiometer.
V
CC
connected to the trim terminal of the ADR44x, is used for fine
adjustment. Resolution depends on the end-to-end resistance
value and the resolution of the selected potentiometer.
2
0.1µF
V
IN
R
SENSE
ADR440/
ADR441/
ADR443/
ADR444/
ADR445
+V
DD
2
V
OUT
6
V
IN
ADR440/
ADR441/
ADR443/
ADR444/
ADR445
GND
4
0.1µF
ADJ V
REF
AD5259
6
V
OUT
I
LOAD
R1
R2
GND
4
10kΩ 10kΩ
Figure 39. Programmable Current Source
HIGH VOLTAGE FLOATING CURRENT SOURCE
Figure 38. Programmable Voltage Source
Use the circuit in Figure 40 to generate a floating current source
with minimal self heating. This particular configuration can
operate on high supply voltages, determined by the breakdown
voltage of the N-channel JFET.
For a completely programmable solution, replace the two
potentiometers in Figure 38 with one Analog Devices dual
digital potentiometer, offered with either an SPI® or an I2C®
interface. These interfaces set the position of the wiper on both
potentiometers and allow the output voltage to be set. Table 9
lists compatible Analog Devices digital potentiometers.
+V
S
SST111
VISHAY
Table 9. Digital Potentiometer Parts
2
V
IN
No. of
No. of
1
Part No.
AD5251
AD5207
AD5242
AD5262
AD5282
AD5252
AD5232
AD5235
ADN2850
Channels
Positions
ITF
I2C
SPI
I2C
SPI
I2C
I2C
SPI
SPI
SPI
R (kΩ)
VDD
5.5
5.5
5.5
15
ADR440/
ADR441/
ADR443/
ADR444/
ADR445
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
64.00
1, 10, 50, 100
10, 50, 100
10, 100, 1M
20, 50, 200
20, 50, 100
1, 10, 50, 100
10, 50, 100
25, 250
256.00
256.00
256.00
256.00
256.00
256.00
1024.00
1024.00
V
OUT
6
2N3904
OP90
15
GND
4
5.5
5.5
5.5
5.5
25, 250
–V
S
1 Can also use a negative supply.
Figure 40. Floating Current Source
Adding a negative supply to the operational amplifier allows
the user also to produce a negative programmable reference,
by connecting the reference output to the inverting terminal
of the operational amplifier. Choose feedback resistors to
minimize errors over temperature.
Rev. A | Page 16 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
PRECISION OUTPUT REGULATOR
(BOOSTED REFERENCE)
V
IN
2
V
IN
2N7002
ADR440/
ADR441/
ADR443/
ADR444/
ADR445
C
15V
IN
0.1µF
V
OUT
6
V
O
R
C
L
1µF
C
L
OUT
0.1µF
200Ω
GND
4
–V
Figure 41. Boosted Output Reference
Higher current drive capability can be obtained, without
sacrificing accuracy, by using the circuit in Figure 41. The
operational amplifier regulates the MOSFET turn-on, forcing
VO to equal the VREF. Current is then drawn from VIN, allowing
increased current drive capability. The circuit allows a 50 mA
load; if higher current drive is required, use a larger MOSFET.
For fast transient response, add a buffer at VO to aid with
capacitive loading.
Rev. A | Page 17 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
1
5
4
6.20 (0.2440)
5.80 (0.2284)
4.00 (0.1574)
3.80 (0.1497)
1.27 (0.0500)
BSC
0.50 (0.0196)
0.25 (0.0099)
× 45°
1.75 (0.0688)
1.35 (0.0532)
0.25 (0.0098)
0.10 (0.0040)
8°
0.51 (0.0201)
0.31 (0.0122)
0° 1.27 (0.0500)
COPLANARITY
0.10
0.25 (0.0098)
0.17 (0.0067)
SEATING
PLANE
0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012-AA
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN
Figure 42. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
3.00
BSC
8
1
5
4
4.90
BSC
3.00
BSC
PIN 1
0.65 BSC
1.10 MAX
0.15
0.00
0.80
0.60
0.40
8°
0°
0.38
0.22
0.23
0.08
COPLANARITY
0.10
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 43. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions show in millimeters
Rev. A | Page 18 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
ORDERING GUIDE
Initial
Temperature
Coefficient
Package (ppm/°C) Description
Accuracy,
(mV) (%)
Output
Voltage (V)
Package
Temperature
Branding Range
Package
Option
Model
ADR440ARZ1
ADR440ARZ-REEL71
ADR440ARMZ1
ADR440ARMZ-REEL71
ADR440BRZ1
ADR440BRZ-REEL71
ADR441ARZ1
ADR441ARZ-REEL71
ADR441ARMZ1
ADR441ARMZ-REEL71
ADR441BRZ1
ADR441BRZ-REEL71
ADR443ARZ1
ADR443ARZ-REEL71
ADR443ARMZ1
ADR443ARMZ-REEL71
ADR443BRZ1
ADR443BRZ-REEL71
ADR444ARZ1
ADR444ARZ-REEL71
ADR444ARMZ1
ADR444ARMZ-REEL71
ADR444BRZ1
ADR444BRZ-REEL71
ADR445ARZ1
ADR445ARZ-REEL71
ADR445ARMZ1
2.048
2.048
2.048
2.048
2.048
2.048
2.500
2.500
2.500
2.500
2.500
2.500
3.000
3.000
3.000
3.000
3.000
3.000
4.096
4.096
4.096
4.096
4.096
4.096
5.000
5.000
5.000
5.000
5.000
5.000
3
3
3
3
0.15 10
0.15 10
0.15 10
0.15 10
8-Lead SOIC_N
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C RM-8
–40°C to +125°C RM-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C RM-8
–40°C to +125°C RM-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C RM-8
–40°C to +125°C RM-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C RM-8
–40°C to +125°C RM-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C R-8
–40°C to +125°C RM-8
–40°C to +125°C RM-8
–40°C to +125°C R-8
–40°C to +125°C R-8
8-Lead SOIC_N
8-Lead MSOP
8-Lead MSOP
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
8-Lead MSOP
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
8-Lead MSOP
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
8-Lead MSOP
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
8-Lead MSOP
8-Lead SOIC_N
8-Lead SOIC_N
R01
R01
1
1
0.05
0.05
3
3
3
3
3
3
0.12 10
0.12 10
0.12 10
0.12 10
R02
R02
1
1
0.04
0.04
3
3
4
4
4
4
0.13 10
0.13 10
0.13 10
0.13 10
R03
R03
1.2
1.2
5
0.04
0.04
3
3
0.13 10
0.13 10
0.13 10
0.13 10
5
5
5
R04
R04
1.6
1.6
6
0.04
0.04
3
3
0.12 10
0.12 10
0.12 10
0.12 10
6
6
6
R05
R05
ADR445ARMZ-REEL71
ADR445BRZ1
ADR445BRZ-REEL71
2
2
0.04
0.04
3
3
1 Z = Pb-free part.
Rev. A | Page 19 of 20
ADR440/ADR441/ADR443/ADR444/ADR445
NOTES
Purchase of licensed I2C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I2C Patent
Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification as defined by Philips.
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05428-0-9/06(A)
Rev. A | Page 20 of 20
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