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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
AD1582/AD1583/AD1584/AD1585
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 World Wide Web Site: http://www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 2001
2.5 V to 5.0 V Micropower, Precision
Series Mode Voltage References
FUNCTIONAL BLOCK DIAGRAM
3-Lead SOT-23
(RT Suffix)
1
2
V
OUT
V
IN
GND
3
AD1582/
AD1583/
AD1584/
AD1585
TOP VIEW
FEATURES
Series Reference (2.5 V, 3 V, 4.096 V, 5 V)
Low Quiescent Current: 65 A max
Current Output Capability: 5 mA
Wide Supply Range: VIN = VOUT + 200 mV to 12 V
Wideband Noise (10 Hz–10 kHz): 50 V rms
Specified Temperature Range: –40C to +85C
Compact, Surface-Mount, SOT-23 Package
TARGET APPLICATIONS
1. Portable, Battery-Powered Equipment. Notebook Computers,
Cellular Phones, Pagers, PDAs, GPSs, and DMMs.
2. Computer Workstations. Suitable for use with a wide range
of video RAMDACs.
3. Smart Industrial Transmitters.
4. PCMCIA Cards.
5. Automotive.
6. Hard Disk Drives.
7. 3 V/5 V 8-Bit/12-Bit Data Converters.
ISUPPLY – A
VSUPPLY – V
800
700
0
2.7 5
400
300
200
100
600
500
*3.076k SOURCE RESISTOR
SHUNT REFERENCE*
AD1582 SERIES REFERENCE
900
Figure 1. Supply Current (
µ
A) vs. Supply Voltage (V)
AD158x Products
3 Electrical Grades
Electrical Tempco
Grade Initial Accuracy ppm/C
AD1582 AD1583/AD1585 AD1584
B 0.08% 0.10% 0.10% 50
C 0.16% 0.20% 0.20% 50
A 0.80% 1.00% 0.98% 100
GENERAL DESCRIPTION
The AD1582, AD1583, AD1584, and AD1585 are a family of
low cost, low power, low dropout, precision bandgap references.
These designs are available as three-terminal (series) devices
and are packaged in the compact SOT-23, 3-lead, surface-mount
package. The versatility of these references makes them ideal for
use in battery powered 3 V or 5 V systems where there may be
wide variations in supply voltage and a need to minimize power
dissipation.
The superior accuracy and temperature stability of the AD1582/
AD1583/AD1584/AD1585 is made possible by the precise
matching and thermal tracking of on-chip components. Patented
temperature drift curvature correction design techniques have
been used to minimize the nonlinearities in the voltage output
temperature characteristic.
These series mode devices (AD1582/AD1583/AD1584/AD1585)
will source or sink up to 5 mA of load current and operate effi-
ciently with only 200 mV of required headroom supply. This
family will draw a maximum 65 µA of quiescent current with
only a 1.0 µA/V variation with supply voltage. The advantage of
these designs over conventional shunt devices is extraordinary.
Valuable supply current is no longer wasted through an input
series resistor and maximum power efficiency is achieved at all
input voltage levels.
The AD1582, AD1583, AD1584, and AD1585 are available in
three grades, A, B, and C, which are provided in a tiny foot-
print, the SOT-23. All grades are specified over the industrial
temperature range of –40°C to +85°C.
AD1582/AD1583/AD1584/AD1585
–2– REV. B
AD1582–SPECIFICATIONS
Model AD1582A AD1582B AD1582C
Min Typ Max Min Typ Max Min Typ Max Unit
OUTPUT VOLTAGE (@ 25°C)
V
O
2.480 2.500 2.520 2.498 2.500 2.502 2.496 2.500 2.504 V
INITIAL ACCURACY ERROR
V
OERR
–20 +20 –2 +2 –4 +4 mV
–0.80 +0.80 –0.08 +0.08 –0.16 +0.16 %
OUTPUT VOLTAGE TEMPERATURE DRIFT 100 50 50 ppm/°C
TEMPERATURE COEFFICIENT (TCV
O
)
–40°C < T
A
< +85°C 40 100 18 50 18 50 ppm/°C
0°C < T
A
< +70°C 35 15 15 ppm/°C
MINIMUM SUPPLY HEADROOM (V
IN
–V
OUT
) 200 200 200 mV
LOAD REGULATION
0 mA < I
OUT
< 5 mA 0.2 0.2 0.2 mV/mA
–5 mA < I
OUT
< 0 mA 0.25 0.25 0.25 mV/mA
–0.1 mA < I
OUT
< +0.1 mA 2.7 2.7 2.7 mV/mA
LINE REGULATION
V
OUT
+200 mV < V
IN
< 12 V
I
OUT
= 0 mA 25 25 25 µV/V
RIPPLE REJECTION (∆V
OUT
/∆V
IN
)
V
IN
= 5 V ± 100 mV (f = 120 Hz) 80 80 80 dB
QUIESCENT CURRENT 65 65 65 µA
SHORT CIRCUIT CURRENT TO GROUND 15 15 15 mA
NOISE VOLTAGE (@ 25°C)
0.1 Hz to 10 Hz 70 70 70 µV p-p
10 Hz to 10 kHz 50 50 50 µV rms
TURN-ON SETTLING TIME TO 0.1%, 100 100 100 µs
C
L
= 0.2 µF
LONG-TERM STABILITY
1000 Hours @ 25°C 100 100 100 ppm/1000 hrs.
OUTPUT VOLTAGE HYSTERESIS 115 115 115 ppm
TEMPERATURE RANGE
Specified Performance (A, B, C) –40 +85 –40 +85 –40 +85 °C
Operating Performance (A, B, C) –55 +125 –55 +125 –55 +125 °C
Specifications subject to change without notice.
(@ TA = TMIN–TMAX, VIN = 5 V, unless otherwise noted.)
–3–
REV. B
AD1582/AD1583/AD1584/AD1585
AD1583–SPECIFICATIONS
Model AD1583A AD1583B AD1583C
Min Typ Max Min Typ Max Min Typ Max Unit
OUTPUT VOLTAGE (@ 25°C)
V
O
2.970 3.000 3.030 2.997 3.000 3.003 2.994 3.000 3.006 V
INITIAL ACCURACY ERROR
V
OERR
–30 +30 –3 +3 –6 +6 mV
–1.0 +1.0 –0.1 +0.1 –0.20 +0.20 %
OUTPUT VOLTAGE TEMPERATURE DRIFT 100 50 50 ppm/°C
TEMPERATURE COEFFICIENT (TCV
O
)
–40°C < T
A
< +85°C 40 100 18 50 18 50 ppm/°C
0°C < T
A
< +70°C 35 15 15 ppm/°C
MINIMUM SUPPLY HEADROOM (V
IN
–V
OUT
) 200 200 200 mV
LOAD REGULATION
0 mA < I
OUT
< 5 mA 0.25 0.25 0.25 mV/mA
–5 mA < I
OUT
< 0 mA 0.40 0.40 0.40 mV/mA
–0.1 mA < I
OUT
< +0.1 mA 2.9 2.9 2.9 mV/mA
LINE REGULATION
V
OUT
+200 mV < V
IN
< 12 V
I
OUT
= 0 mA 25 25 25 µV/V
RIPPLE REJECTION (∆V
OUT
/∆V
IN
)
V
IN
= 5 V ± 100 mV (f = 120 Hz) 80 80 80 dB
QUIESCENT CURRENT 65 65 65 µA
SHORT CIRCUIT CURRENT TO GROUND 15 15 15 mA
NOISE VOLTAGE (@ 25°C)
0.1 Hz to 10 Hz 85 85 85 µV p-p
10 Hz to 10 kHz 60 60 60 µV rms
TURN-ON SETTLING TIME TO 0.1% 120 120 120 µs
C
L
= 0.2 µF
LONG-TERM STABILITY
1000 Hours @ 25°C 100 100 100 ppm/1000 hrs.
OUTPUT VOLTAGE HYSTERESIS 115 115 115 ppm
TEMPERATURE RANGE
Specified Performance (A, B, C) –40 +85 –40 +85 –40 +85 °C
Operating Performance (A, B, C) –55 +125 –55 +125 –55 +125 °C
Specifications subject to change without notice.
(@ TA = TMIN–TMAX, VIN = 5 V, unless otherwise noted.)
AD1582/AD1583/AD1584/AD1585
–4– REV. B
AD1584–SPECIFICATIONS
Model AD1584A AD1584B AD1584C
Min Typ Max Min Typ Max Min Typ Max Unit
OUTPUT VOLTAGE (@ 25°C)
V
O
4.056 4.096 4.136 4.092 4.096 4.100 4.088 4.096 4.104 V
INITIAL ACCURACY ERROR
V
OERR
–40 +40 –4 +4 –8 +8 mV
–0.98 +0.98 –0.1 +0.1 –0.2 +0.2 %
OUTPUT VOLTAGE TEMPERATURE DRIFT
1
100 50 50 ppm/°C
TEMPERATURE COEFFICIENT (TCV
O
)
–40°C < T
A
< +85°C 40 100 18 50 18 50 ppm/°C
0°C < T
A
< +70°C 35 15 15 ppm/°C
MINIMUM SUPPLY HEADROOM (V
IN
–V
OUT
) 200 200 200 mV
LOAD REGULATION
0 mA < I
OUT
< 5 mA 0.32 0.32 0.32 mV/mA
–5 mA < I
OUT
< 0 mA 0.40 0.40 0.40 mV/mA
–0.1 mA < I
OUT
< +0.1 mA 3.2 3.2 3.2 mV/mA
LINE REGULATION
V
OUT
+200 mV < V
IN
< 12 V
I
OUT
= 0 mA 25 25 25 µV/V
RIPPLE REJECTION (∆V
OUT
/∆V
IN
)
V
IN
= 5 V ± 100 mV (f = 120 Hz)
2
80 80 80 dB
QUIESCENT CURRENT 65 65 65 µA
SHORT CIRCUIT CURRENT TO GROUND 15 15 15 mA
NOISE VOLTAGE (@ 25°C)
0.1 Hz to 10 Hz 110 110 110 µV p-p
10 Hz to 10 kHz 90 90 90 µV rms
TURN-ON SETTLING TIME TO 0.1% 140 140 140 µs
C
L
= 0.2 µF
LONG-TERM STABILITY
1000 Hours @ 25°C 100 100 100 ppm/1000 hrs.
OUTPUT VOLTAGE HYSTERESIS 115 115 115 ppm
TEMPERATURE RANGE
Specified Performance (A, B, C) –40 +85 –40 +85 –40 +85 °C
Operating Performance (A, B, C) –55 +125 –55 +125 –55 +125 °C
Specifications subject to change without notice.
(@ TA = TMIN–TMAX, VIN = 5 V, unless otherwise noted.)
–5–
REV. B
AD1582/AD1583/AD1584/AD1585
AD1585–SPECIFICATIONS
Model AD1585A AD1585B AD1585C
Min Typ Max Min Typ Max Min Typ Max Unit
OUTPUT VOLTAGE (@ 25°C)
V
O
4.950 5.000 5.050 4.995 5.000 5.005 4.990 5.000 5.010 V
INITIAL ACCURACY ERROR
V
OERR
–50 +50 –5 +5 –10 +10 mV
–1.0 +1.0 –0.10 +0.10 –0.20 +0.20 %
OUTPUT VOLTAGE TEMPERATURE DRIFT 100 50 50 ppm/°C
TEMPERATURE COEFFICIENT (TCV
O
)
–40°C < T
A
< +85°C 40 100 18 50 18 50 ppm/°C
0°C < T
A
< +70°C 35 15 15 ppm/°C
MINIMUM SUPPLY HEADROOM (V
IN
–V
OUT
) 200 200 200 mV
LOAD REGULATION
0 mA < I
OUT
< 5 mA 0.40 0.40 0.40 mV/mA
–5 mA < I
OUT
< 0 mA 0.40 0.40 0.40 mV/mA
–0.1 mA < I
OUT
< +0.1 mA 4 4 4 mV/mA
LINE REGULATION
V
OUT
+200 mV < V
IN
< 12 V
I
OUT
= 0 mA 25 25 25 µV/V
RIPPLE REJECTION (∆V
OUT
/∆V
IN
)
V
IN
= 6 V ± 100 mV (f = 120 Hz) 80 80 80 dB
QUIESCENT CURRENT 65 65 65 µA
SHORT CIRCUIT CURRENT TO GROUND 15 15 15 mA
NOISE VOLTAGE (@ 25°C)
0.1 Hz to 10 Hz 140 140 140 µV p-p
10 Hz to 10 kHz 100 100 100 µV rms
TURN-ON SETTLING TIME TO 0.1% 175 175 175 µs
C
L
= 0.2 µF
LONG-TERM STABILITY
1000 Hours @ 25°C 100 100 100 ppm/1000 hrs.
OUTPUT VOLTAGE HYSTERESIS 115 115 115 ppm
TEMPERATURE RANGE
Specified Performance (A, B, C) –40 +85 –40 +85 –40 +85 °C
Operating Performance (A, B, C) –55 +125 –55 +125 –55 +125 °C
Specifications subject to change without notice.
(@ TA = TMIN–TMAX, VIN = 6 V, unless otherwise noted)
AD1582/AD1583/AD1584/AD1585
–6– REV. B
ABSOLUTE MAXIMUM RATINGS
1
V
IN
to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 V
Internal Power Dissipation
2
SOT-23 (RT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 mW
Storage Temperature Range . . . . . . . . . . . . –65°C to +125°C
Specified Temperature Range
AD1582/AD1583/AD1584/AD1585RT . . –40°C to +85°C
Lead Temperature, Soldering
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . 215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
NOTES
1
Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent 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.
2
Specification is for device in free air at 25°C: SOT-23 Package: θ
JA
= 300°C/W.
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 AD1582/AD1583/AD1584/AD1585 feature 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.
PACKAGE BRANDING INFORMATION
Four marking fields identify the device generic, grade and date
of processing. The first field is the product identifier. A “2/3/4/5”
identifies the generic as the AD1582/AD1583/AD1584/AD1585.
The second field indicates the device grade; “A,” “B,” and “C.”
In the third field a numeral or letter indicates the calendar year;
“7” for 1997. . . , “A” for 2001. . . The fourth field uses letters
A-Z to represent a two week window within the calendar year,
starting with “A” for the first two weeks of January.
ORDERING GUIDE
Initial Initial
Output Accuracy Accuracy Temperature Package Package Top Number of
Model Voltage mV % Coefficient Description Option Mark Parts per Reel
AD1582ART-Reel 2.50 20 0.80% 100 SOT-23 RT-3 2A0A 10,000
AD1582ART-Reel7 2.50 20 0.80% 100 SOT-23 RT-3 2A0A 3,000
AD1582BRT-Reel 2.50 2 0.08% 50 SOT-23 RT-3 2B0A 10,000
AD1582BRT-Reel7 2.50 2 0.08% 50 SOT-23 RT-3 2B0A 3,000
AD1582CRT-Reel 2.50 4 0.16% 50 SOT-23 RT-3 2C0A 10,000
AD1582CRT-Reel7 2.50 4 0.16% 50 SOT-23 RT-3 2C0A 3,000
AD1583ART-Reel 3.00 30 1.00% 100 SOT-23 RT-3 3A0A 10,000
AD1583ART-Reel7 3.00 30 1.00% 100 SOT-23 RT-3 3A0A 3,000
AD1583BRT-Reel 3.00 3 0.10% 50 SOT-23 RT-3 3B0A 10,000
AD1583BRT-Reel7 3.00 3 0.10% 50 SOT-23 RT-3 3B0A 3,000
AD1583CRT-Reel 3.00 6 0.20% 50 SOT-23 RT-3 3C0A 10,000
AD1583CRT-Reel7 3.00 6 0.20% 50 SOT-23 RT-3 3C0A 3,000
AD1584ART-Reel 4.096 40 0.98% 100 SOT-23 RT-3 4A0A 10,000
AD1584ART-Reel7 4.096 40 0.98% 100 SOT-23 RT-3 4A0A 3,000
AD1584BRT-Reel 4.096 4 0.10% 50 SOT-23 RT-3 4B0A 10,000
AD1584BRT-Reel7 4.096 4 0.10% 50 SOT-23 RT-3 4B0A 3,000
AD1584CRT-Reel 4.096 8 0.20% 50 SOT-23 RT-3 4C0A 10,000
AD1584CRT-Reel7 4.096 8 0.20% 50 SOT-23 RT-3 4C0A 3,000
AD1585ART-Reel 5.00 50 1.00% 100 SOT-23 RT-3 5A0A 10,000
AD1585ART-Reel7 5.00 50 1.00% 100 SOT-23 RT-3 5A0A 3,000
AD1585BRT-Reel 5.00 5 0.10% 50 SOT-23 RT-3 5B0A 10,000
AD1585BRT-Reel7 5.00 5 0.10% 50 SOT-23 RT-3 5B0A 3,000
AD1585CRT-Reel 5.00 10 0.20% 50 SOT-23 RT-3 5C0A 10,000
AD1585CRT-Reel7 5.00 10 0.20% 50 SOT-23 RT-3 5C0A 3,000
WARNING!
ESD SENSITIVE DEVICE
AD1582/AD1583/AD1584/AD1585
–7–
REV. B
PARAMETER DEFINITION
Temperature Coefficient (TCV
O
)
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 VT VT
VCTT
O
OO
O
/]°
[
=
()
−
()
°
()
×−
()
×
21
21
6
25 10
Where:
V
O
(25⬚C) = V
O
at 25⬚C.
V
O
(T
1
) = V
O
at temperature1.
V
O
(T
2
) = V
O
at temperature2.
Line Regulation (∆V
O
/∆V
IN
)
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 (∆V
O
/∆I
LOAD
)
The change in output voltage 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 Ω of dc output resistance.
Long Term Stability (∆V
O
)
Typical shift of output voltage at 25⬚C on a sample of parts
subjected to operation life test of 1000 hours at 125⬚C:
∆
∆
VVtVt
V ppm Vt Vt
Vt
OO O
O
OO
O
=
()
−
()
[]
=
()
−
()
()
×
01
01
0
6
10
Where:
V
O
(t
0
) = V
O
at 25⬚C at time 0.
V
O
(t
1
) = V
O
at 25⬚C after 1000 hours operation at 125⬚C.
Thermal Hysteresis (V
O_HYS
)
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
V ppm
VCV
VC
O HYS O O TC
O HYS
OOTC
O
__
_
_
=
()
−
[]
=
°
()
−
°
()
×
25
25
25 106
o
Where:
V
O
(25⬚C) = V
O
at 25⬚C.
V
O_TC
= V
O
at 25⬚C after temperature cycle at +25⬚C to
–40⬚C to +85⬚C and back to +25⬚C.
Operating Temperature
This is defined as the temperature extremes at which the device
will still function. Parts may deviate from their specified perfor-
mance outside the specified temperature range.
AD1582/AD1583/AD1584/AD1585
–8– REV. B
–Typical Performance Characteristics
ppm/C
6
0
–60 50–50 –10 10
14
8
4
2
12
10
30
# OF PARTS
22
16
20
18
–40 –30 –20 0 20 40
TPC 1. Typical Output Voltage Temperature Drift
Distribution
VOUT – ERROR
50
15
0
–100% 1.00%–0.60% –0.20% 0.20% 0.60%
45
20
10
5
35
25
40
30
# OF PARTS
TPC 2. Typical Output Voltage Error Distribution
TEMPERATURE – C
V
OUT
–60 120–40 –20 0 20 40 60 80 100
2.510
2.508
2.492
2.500
2.498
2.496
2.494
2.504
2.502
2.506
TPC 3. Typical Temperature Drift Characteristic Curves
V
IN
– Volts
024681012
0
0.25
0.20
0.15
0.10
0.35
0.30
0.40
0.05
1585
1582
mV/mA
TPC 4. Load Regulation vs. V
IN
–20
–40
–60
–80
–70
–30
–50
I
OUT
– mA
V/V
0
–90
–51–4–3–2–10 23 45
1582
1585
–10
TPC 5. Line Regulation vs. I
LOAD
1E+04
1E+031E+021E+01
1E+02
1E+03
1E+04 1E+05
IOUT = 0
IOUT = 1mA
FREQUENCY – Hz
nV/ Hz
TPC 6. Noise Spectral Density
AD1582/AD1583/AD1584/AD1585
–9–
REV. B
THEORY OF OPERATION
The AD1582/AD1583/AD1584/AD1585 family uses the
“bandgap” concept to produce stable, low temperature coefficient
voltage references suitable for high accuracy data acquisition
components and systems. This family of precision references
makes use of the underlying temperature characteristics of a
silicon transistor’s base-emitter voltage in the forward biased
operating region. Under this condition, all such transistors have
a –2 mV/°C temperature coefficient (TC) and a V
BE
that, when
extrapolated to absolute zero, 0°K, (with collector current propor-
tional to absolute temperature) approximates the silicon bandgap
voltage. By summing a voltage that has an equal and opposite
temperature coefficient of +2 mV/°C with the V
BE
of a forward-
biased transistor, an almost zero TC reference can be developed.
In the AD1582/AD1583/AD1584/AD1585 simplified circuit
diagram shown in Figure 2, such a compensating voltage, V1, is
derived by driving two transistors at different current densities
and amplifying the resultant V
BE
difference (∆V
BE
—which has
a positive TC). The sum (V
BG
) of V
BE
and V1 is then buffered
and amplified to produce stable reference voltage outputs of
2.5 V, 3 V, 4.096 V, and 5 V.
R3 R4
VBE R2 R6
R5
VOUT
VIN
VBG
GND
V1
+
–
R1
+
–
Figure 2. Simplified Schematic
APPLYING THE AD1582/AD1583/AD1584/AD1585
The AD1582/AD1583/AD1584/AD1585 is a family of series
references that can be utilized for many applications. To achieve
optimum performance with these references, only two external
components are required. Figure 3 shows the AD1582 config-
ured for operation under all loading conditions. With a simple
4.7 µF capacitor attached to the input and a 1 µF capacitor
applied to the output, the devices will achieve specified perfor-
mance for all input voltage and output current requirements.
For best transient response, add a 0.1 µF capacitor in parallel with
the 4.7 µF. While a 1 µF output capacitor will provide stable
performance for all loading conditions, the AD1582 can operate
under low (–100 µA < I
OUT
< 100 µA) current conditions with
just a 0.2 µF output capacitor. The 4.7 µF capacitor on the input
can be reduced to 1 µF in this condition.
Unlike conventional shunt reference designs, the AD1582/
AD1583/AD1584/AD1585 family provides stable output voltages
at constant operating current levels. When properly decoupled,
as shown in Figure 3, these devices can be applied to any circuit
and provide superior low power solutions.
+
–
VOUT1F
1
2
VIN
4.7F
3
AD1582/
AD1583/
AD1584/
AD1585
Figure 3. Typical Connection Diagram
TEMPERATURE PERFORMANCE
The AD1582/AD1583/AD1584/AD1585 family of references is
designed for applications where temperature performance is
important. Extensive temperature testing and characterization
ensures that the device’s performance is maintained over the
specified temperature range.
The error band guaranteed with the AD1582/AD1583/AD1584/
AD1585 family is the maximum deviation from the initial value at
25°C. Thus, for a given grade of the AD1582/AD1583/AD1584/
AD1585, the designer can easily determine the maximum total
error by summing initial accuracy and temperature variation
(e.g., for the AD1582BRT, the initial tolerance is ±2 mV, the
temperature error band is ±8 mV, thus the reference is guaran-
teed to be 2.5 V ± 10 mV from –40°C to +85°C).
Figure 4 shows the typical output voltage drift for the AD1582
and illustrates the methodology. The box in Figure 4 is bounded
on the x-axis by operating temperature extremes, and on the
y-axis by the maximum and minimum output voltages observed
over the operating temperature range. The slope of the diagonal
drawn from the initial output value at 25°C to the output values at
+85°C and –40°C determines the performance grade of the device.
Duplication of these results requires a test system that is highly
accurate with stable temperature control. Evaluation of the
AD1582 will produce curves similar to those in TPC 3 and Fig-
ure 4, but output readings may vary depending upon the test
methods and test equipment utilized.
TEMPERATURE – C
V
OUT
– Volts
–60 120–40 –200 20406080100
2.510
2.509
2.501
2.505
2.504
2.503
2.502
2.507
2.506
2.508
Figure 4. Output Voltage vs. Temperature
AD1582/AD1583/AD1584/AD1585
–10– REV. B
VOLTAGE OUTPUT NONLINEARITY VS. TEMPERATURE
When using a voltage reference with data converters, it is impor-
tant to understand the impact that temperature drift can have
on the converter’s performance. The nonlinearity of the refer-
ence output drift represents additional error that cannot easily
be calibrated out of the overall system. To better understand the
impact such a drift can have on a data converter, refer to Figure
5 where the measured drift characteristic is normalized to the
end point average drift. The residual drift error of the AD1582
of approximately 200 ppm demonstrates that this family of
references is compatible with systems that require
12-bit accurate temperature performance.
TEMPERATURE –
C
250
–50
–50 100–250 255075
200
150
100
50
0
VOUT
– ppm
Figure 5. Residual Drift Error
OUTPUT VOLTAGE HYSTERESIS
High performance industrial equipment manufacturers may
require the AD1582/AD1583/AD1584/AD1585 family to maintain
a consistent output voltage error at 25°C after the references are
operated over the full temperature range. While all references
exhibit a characteristic known as output voltage hysteresis, the
AD1582/AD1583/AD1584/AD1585 family is designed to mini-
mize this characteristic. This phenomenon can be quantified by
measuring the change in the 25°C output voltage after tem-
perature excursions from 85°C to 25°C, and –40°C to +25°C.
Figure 12 displays the distribution of the AD1582 output volt-
age hysteresis.
pp
m
–700 –450 –200 50 300 550
0
10
20
30
40
50
60
70
80
# OF PARTS
Figure 6. Output Voltage Hysteresis Distribution
SUPPLY CURRENT VS. TEMPERATURE
The quiescent current for the AD1582/AD1583/AD1584/AD1585
family of references will vary slightly over temperature and input
supply range. Figure 7 demonstrates the typical performance
for the AD1582 reference when varying both temperature and
supply voltage. As is evident from the graph, the AD1582 supply
current increases only 1.0 µA/V, making this device extremely
attractive for use in applications where there may be wide varia-
tions in supply voltage and a need to minimize power dissipation.
VIN – Volts
IQ – A
100
80
034567891011
60
40
20
TA = +85C TA = +25C
TA = –40C
Figure 7. Typical Supply Current over Temperature
SUPPLY VOLTAGE
One of the ideal features of AD1582/AD1583/AD1584/AD1585 is
its low supply voltage headroom. The part can operate at
supply voltage as low as 200 mV above V
OUT
and up to 12 V.
However, if negative voltage is inadvertently applied to V
IN
with
respect to ground or any negative transient, >5 V is coupled to
V
IN
, the device can be damaged.
AD1582/AD1583/AD1584/AD1585
–11–
REV. B
AC PERFORMANCE
To successfully apply the AD1582/AD1583/AD1584/AD1585
family of references, it is important to understand the effects of
dynamic output impedance and power supply rejection. In
Figure 8a, a voltage divider is formed by the AD1582’s output
impedance and the external source impedance. Figure 8b shows
the effect of varying the load capacitor on the reference output.
Power supply rejection ratio (PSRR) should be determined when
characterizing the ac performance of a series voltage reference.
Figure 9a shows a test circuit used to measure PSRR, and
Figure 9b demonstrates the AD1582’s ability to attenuate line
voltage ripple.
2X V
OUT
10k
10k
2V
100A
10k
2k
V
LOAD
DC 5V
5F
1F
DUT
X1
Figure 8a. Output Impedance Test Circuit
100
1
0.1
OHM
10
FREQUENCY – Hz
1E+01 1E+02 1E+03 1E+04 1E+05 1E+06
1F CAP
1585
1582
Figure 8b. Output Impedance vs. Frequency
5V 100mV
0.22
FDUT
0.22
F
V
OUT
10V
10k
10k
200mV
X1
Figure 9a. Ripple Rejection Test Circuit
FREQUENCY – Hz
100
90
0
1.E+00 1.E+061.E+01 1.E+02 1.E+03 1.E+04 1.E+05
50
20
PSRR – dB
80
70
60
40
30
10
1582
1585
Figure 9b. Ripple Rejection vs. Frequency
NOISE PERFORMANCE AND REDUCTION
The noise generated by the AD1582 is typically less then
70 µV p-p over the 0.1 Hz to 10 Hz frequency band. Figure 10
shows the 0.1 Hz to 10 Hz noise of a typical AD1582. The noise
measurement is made with a high gain bandpass filter. Noise in
a 10 Hz to 10 kHz region is approximately 50 µV rms. Figure 11
shows the broadband noise of a typical AD1582. If further noise
reduction is desired, a 1-pole low-pass filter may be added
between the output pin and ground. A time constant of 0.2 ms
will have a –3 dB point at roughly 800 Hz, and will reduce the
high frequency noise to about 16 µV rms. It should be noted,
however, that while additional filtering on the output may improve
the noise performance of the AD1582/AD1583/AD1584/AD1585
family, the added output impedance could degrade the ac per-
formance of the references.
100
90
10
0%
10
V 1s
Figure 10. 0.1–10 Hz Voltage Noise
10
0%
100
90
10ms
100
V
Figure 11. 10 Hz to 10 kHz Wideband Noise
AD1582/AD1583/AD1584/AD1585
–12– REV. B
TURN-ON TIME
Many low power instrument manufacturers are becoming increas-
ingly concerned with the turn-on characteristics of the components
being used in their systems. Fast turn-on components often enable
the end user to save power by keeping power off when it is not
needed. Turn-on settling time is defined as the time required, after
the application of power (cold start), for the output voltage to
reach its final value within a specified error. The two major fac-
tors affecting this are the active circuit settling time and the time
required for the thermal gradients on the chip to stabilize. Fig-
ure 12a shows the turn-on settling and transient response test
circuit. Figure 12b displays the turn-on characteristic of the
AD1582. This characteristic is generated from cold-start opera-
tion and represents the true turn-on waveform after power up.
Figure 12c shows the fine settling characteristics of the AD1582.
Typically, the reference settles to within 0.1% of its final value
in about 100 µs.
The device can momentarily draw excessive supply current
when V
SUPPLY
is slightly below the minimum specified level.
Power supply resistance must be low enough to ensure reliable
turn-on. Fast power supply edges minimize this effect.
0V OR 10V
0V TO 10V
5V OR 10V
0V OR 5V
0.22F
DUT
0.22F
V
OUT
10k
10k
X1
Figure 12a. Turn-On/Transient Response Test Circuit
10
0%
100
90
20
s
5V
20
s
1V
Figure 12b. Turn-On Characteristics
10
0%
100
90
20
s
5V
20
s
1mV
Figure 12c. Turn-On Settling
DYNAMIC PERFORMANCE
Many A/D and D/A converters present transient current loads
to the reference, and poor reference response can degrade the
converter’s performance. The AD1582/AD1583/AD1584/AD1585
family of references has been designed to provide superior static
and dynamic line and load regulation. Since these series refer-
ences are capable of both sourcing and sinking large current loads,
they exhibit excellent settling characteristics.
Figure 13 displays the line transient response for the AD1582.
The circuit utilized to perform such a measurement is displayed
in Figure 12a, where the input supply voltage is toggled from
5 V to 10 V and the input and output capacitors are each 0.22 µF.
Figures 14 and 15 show the load transient settling characteris-
tics for the AD1582 when load current steps of 0 mA to 5 mA
and 0 mA to –1 mA are applied. The input supply voltage
remains constant at 5 V, the input decoupling and output load
capacitors are 4.7 µF and 1 µF respectively, and the output current
is toggled. For both positive and negative current loads, the
reference responses settle very quickly and exhibit initial voltage
spikes less than 10 mV.
10
0%
100
90
50
s
5V
50
s
200mV
Figure 13. Line Transient Response
10
0%
100
90
20
s
5V
20
s
5mV
Figure 14. Load Transient Response (0 mA to 5 mA Load)
10
0%
100
90
20
s
5V
20
s
5mV
Figure 15. Load Transient Response (0 mA to –1 mA Load)
AD1582/AD1583/AD1584/AD1585
–13–
REV. B
Surface-Mount Package
SOT-23
0.1200 (3.048)
0.1102 (2.799)
PIN 1
0.055 (1.397)
0.0470 (1.194)
0.0236 (0.599)
0.0177 (0.450)
0.1040 (2.642)
0.0827 (2.101)
0.0413 (1.049)
0.0374 (0.950)
0.0807 (2.050)
0.0701 (1.781)
1 2
3
SEATING
PLANE
0.0440 (1.118)
0.0320 (0.813)
0.0040 (0.102)
0.0005 (0.013)
0.0210 (0.533)
0.0146 (0.371) 0.027 (0.686)
REF
0.0059 (0.150)
0.0034 (0.086)
0.0100 (0.254)
0.0050 (0.127)
TAPE AND REEL DIMENSIONS
Dimensions shown in millimeters.
1.0 MIN
4.0 0.10
2.0 0.05
1.75
0.10
1.5 +0.05
–0.00
8.0
0.30
3.1 0.1
DIRECTION OF UNREELING
0.75
MIN
3.5
0.05
0.30
0.05
1.8 0.1
2.7
0.1
1.5 MIN
20.2
MIN
180 (7")
OR
330 (13")
14.4 MAX
8.4 + 1.5
–0.0
13.0
0.2
50 (7" REEL) MIN
OR
100 (13" REEL) MIN
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
C00701–2.5–1/01 (rev. B)
PRINTED IN U.S.A.
