High Precision,
2.5 V IC Reference
AD580
FEATURES
Laser-trimmed to high accuracy: 2.500 V ±0.4%
3-terminal device: voltage in/voltage out
Excellent temperature stability: 10 ppm/°C (AD580M, U)
Excellent long-term stability: 250 µV (25 µV/month)
Low quiescent current: 1.5 mA maximum
Small, hermetic IC package: TO-52 can
MIL-STD-883 compliant versions available
FUNCTIONAL BLOCK DIAGRAM
+E
BOTTOM
VIEW
E
OUT
–E
Figure 1.
GENERAL DESCRIPTION
The AD580
1
is a 3-terminal, low cost, temperature-
compensated, bandgap voltage reference, which provides a fixed
2.5 V output for inputs between 4.5 V and 30 V. A unique
combination of advanced circuit design and laser-wafer
trimmed thin film resistors provide the AD580 with an initial
tolerance of ±0.4%, a temperature stability of better than 10
ppm/°C, and long-term stability of better than 250 µV. In
addition, the low quiescent current drain of 1.5 mA maximum
offers a clear advantage over classical Zener techniques.
The AD580 is recommended as a stable reference for all 8-, 10-,
and 12-bit D/A converters that require an external reference. In
addition, the wide input range of the AD580 allows operation
with 5 volt logic supplies, making the AD580 ideal for digital
panel meter applications or whenever only a single logic power
supply is available.
The AD580J, K, L, and M are specified for operation over the
0°C to +70°C temperature range; the AD580S, T, and U are
specified for operation over the extended temperature range of
–55°C to +125°C.
PRODUCT HIGHLIGHTS
1.
Laser-trimming of the thin film resistors minimizes the
AD580 output error. For example, the AD580L output
tolerance is ±10 mV.
The three-terminal voltage in/voltage out operation of the
AD580 provides regulated output voltage without any
external components.
The AD580 provides a stable 2.5 V output voltage for input
voltages between 4.5 V and 30 V. The capability to provide
a stable output voltage using a 5 V input makes the AD580
an ideal choice for systems that contain a single logic
power supply.
Thin film resistor technology and tightly controlled bipolar
processing provide the AD580 with temperature stabilities
to 10 ppm/°C and long-term stability better than 250 µV.
The low quiescent current drain of the AD580 makes it
ideal for CMOS and other low power applications.
The AD580 is available in versions compliant with MIL-
STD-883. Refer to the Analog Devices Military Products
Data Book or the current AD580/AD883B data sheet for
detailed specifications.
2.
3.
4.
5.
6.
1
Protected by U.S. Patent Numbers 3,887,863; RE30,586.
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: 781.326.8703
© 2004 Analog Devices, Inc. All rights reserved.
00525-B-001
AD580
TABLE OF CONTENTS
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 4
AD580 Chip Dimensions And Pad Layout............................... 4
ESD Caution.................................................................................. 4
Theory of Operation ........................................................................ 5
Voltage Variation versus Temperature ....................................... 5
Noise Performance ....................................................................... 6
The AD580 as a Current Limiter.................................................6
The AD580 as a Low Power, Low Voltage, Precision Reference
for Data Converters.......................................................................7
Outline Dimensions ..........................................................................8
Ordering Guide .............................................................................8
REVISION HISTORY
8/04—Changed from Rev. A to Rev. B
Updated Format................................................................ Universal
Rev. B | Page 2 of 8
AD580
SPECIFICATIONS
Table 1. V
IN
= 15 V and 25°C
Model
OUTPUT VOLTAGE TOLERANCE
Error from Nominal 2.500 V Output
OUTPUT VOLTAGE CHANGE
T
MIN
to T
MAX
LINE REGULATION
7 V ≤ V
IN
≤ 30 V
4.5 V ≤ V
IN
≤ 7 V
LOAD REGULATION
∆I = 10 mA
QUIESCENT CURRENT
NOISE (0.1 Hz to 10 Hz)
STABILITY
Long Term
Per Month
TEMPERATURE PERFORMANCE
Specified
Operating
Storage
PACKAGE OPTION
2
TO-52 (H-03A)
AD580J
Min Typ Max
±75
15
85
1.5
0.3
6
1
3
10
1.5
1.5
0.3
AD580K
Min Typ Max
±25
7
40
4
2
10
1.5
AD580L
Min Typ Max
±10
4.3
25
2
1
10
1.5
AD580M
Min Typ Max
±10
1.75
10
2
1
10
1.5
Units
mV
mV
ppm/°C
mV
mV
mV
mA
µV p-p
µV
µV
°C
°C
°C
1.0
8
250
25
0
–55
–65
1.0
8
250
25
0
–55
–65
1.0
8
250
25
0
–55
–65
1.0
8
250
25
0
–55
–65
+70
+125
+175
AD580JH
+70
+125
+175
AD580KH
+70
+125
+175
AD580LH
+70
+125
+175
AD580MH
Table 2.
Model
OUTPUT VOLTAGE TOLERANCE
Error from Nominal 2.500 V Output
OUTPUT VOLTAGE CHANGE
T
MIN
to T
MAX
LINE REGULATION
7 V ≤ V
IN
≤ 30 V
4.5 V ≤ V
IN
≤ 7 V
LOAD REGULATION
∆I = 10 mA
QUIESCENT CURRENT
NOISE (0.1 Hz to 10 Hz)
STABILITY
Long Term
Per Month
TEMPERATURE PERFORMANCE
Specified
Operating
Storage
PACKAGE OPTION
2
TO-52 (H-03A)
Min
AD580S
Typ
Max
±25
1
25
55
1.5
0.3
6
3
10
1.5
Min
AD580T
Typ
Max
±10
11
25
2
1
10
1.5
Min
AD580U
Typ
Max
±10
4.5
10
2
1
10
1.5
Units
mV
mV
ppm/°C
mV
mV
mV
mA
µV p-p
µV
µV
+125
+150
+175
AD580UH
°C
°C
°C
1.0
8
250
25
–55
–55
–65
AD580SH
1.0
8
250
25
1.0
8
250
25
+125
+150
+175
–55
–55
–65
AD580TH
+125
+150
+175
–55
–55
–65
1
Specifications shown in
boldface
are tested on all production units at final electrical test. Results from those tests are used to calculate outgoing quality levels. All min
and max specifications are guaranteed, although only those shown in
boldface
are tested on all production units.
2
H = Metal Can.
Rev. B | Page 3 of 8
AD580
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
Input Voltage
Power Dissipation @ 25°C
Ambient Temperature
Derate above 25°C
Lead Temperature (Soldering
10 sec)
Thermal Resistance
Junction-to-Case
Junction-to-Ambient
Rating
40 V
350 mW
2.8 mW/°C
300°C
AD580 CHIP DIMENSIONS AND PAD LAYOUT
Dimensions shown in inches and (millimeters).
0.075 (1.90)
+E
0.046
(1.16)
100°C
360°C/W
E
OUT
*
–E
00525-B-002
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 listed in the operational sections
of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
*BOTH E
OUT
PADS MUST BE CONNECTED TO THE OUTPUT.
Figure 2.
The AD580 is also available in chip form. Consult the factory
for specifications and applications information.
ESD 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 this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
Rev. B | Page 4 of 8
AD580
THEORY OF OPERATION
The AD580 family (AD580, AD581, AD584, AD589) uses the
bandgap concept to produce a stable, low temperature coef-
ficient voltage reference suitable for high accuracy data acqui-
sition components and systems. The device makes use of the
underlying physical nature of a silicon transistor base-emitter
voltage in the forward-biased operating region. All such tran-
sistors have approximately a –2 mV/°C temperature coefficient,
unsuitable for use directly as a low TC reference. Extrapolation
of the temperature characteristic of any one of these devices to
absolute zero (with an emitter current propor-tional to the
absolute temperature), however, reveals that it will go to a V
BE
of
1.205 V at 0 K, as shown in Figure 3. Thus, if a voltage could be
developed with an opposing temperature coefficient to sum
with V
BE
to total 1.205 V, a 0 TC reference would result and
operation from a single, low voltage supply would be possible.
The AD580 circuit provides such a compensating voltage, V1 in
Figure 4, by driving two transistors at different current densities
and amplifying the resulting V
BE
difference (∆V
BE
—which now
has a positive TC). The sum, V
Z
, is then buffered and amplified
up to 2.5 V to provide a usable reference-voltage output. Figure
5 shows the schematic diagram of the AD580.
The AD580 operates as a 3-terminal reference, meaning that no
additional components are required for biasing or current
setting. The connection diagram, Figure 6, is quite simple.
COM
1.5
CONSTANT SUM = 1.205V
1.205
FOR BOTH
DEVICES
1.0
+E
4.5
≤
V
IN
≤
30V
E
OUT
LOAD
–E
00525-B-006
+V
IN
R8
I
2
≅
I
1
R4
Q2
8A
Q1
A
R2
V
BE
(Q1)
R5
V
Z
= V
BE
+ V
1
= V
BE
+ 2
= V
BE
+ 2
= 1.205V
R
1
∆
V
BE
R
2
00525-B-004
R7
V
OUT
= V
Z
1 +
R
4
= 2.5V
R
5
∆
V
BE
2I
1
= I
1
+ I
2
COM
R1
V
1
= 2
R
1
∆
V
BE
R
2
J
R
1
kT
ln
1
R
2
q
J
2
Figure 4. Basic Bandgap-Reference Regulator Circuit
+E
R12
Q14
R13
Q13
Q4
Q3
Q7
R8
Q10
Q8
R7
Q11
R6
Q12
Q6
Q9
Q2
8A
R3
Q1
A
Q15
C1
Q5
R10
R9
R4
2.5V
OUT
R2
R1
R5
00525-B-005
R11
–E
Figure 5. Schematic Diagram
JUNCTION VOLTAGE (V)
AD580
0.5
V
BE
VS. TEMPERATURE
FOR TWO TYPICAL
DEVICES (I
E
α
T)
00525-B-003
0
–273°C
0K
REQUIRED
COMPENSATION
VOLTAGE–
SAME DEVICES
–200°C
73K
–100°C
173K
TEMPERATURE
0°C
273K
Figure 6. Connection Diagram
VOLTAGE VARIATION VERSUS TEMPERATURE
Some confusion exists in the area of defining and specifying
reference voltage error over temperature. Historically, references
are characterized using a maximum deviation per degree
Centigrade; i.e., 10 ppm/°C. However, because of the
inconsistent nonlinearities in Zener references (butterfly or S
type characteristics), most manufacturers use a maximum limit
error band approach to characterize their references. This
technique measures the output voltage at 3 to 5 different
temperatures and guarantees that the output voltage deviation
will fall within the guaranteed error band at these discrete
temperatures. This approach, of course, makes no mention or
guarantee of performance at any other temperature within the
operating temperature range of the device.
100°C
373K
Figure 3. Extrapolated Variation of Base-Emitter Voltage with Temperature
(I
E
αT), and Required Compensation, Shown for Two Different Devices
Rev. B | Page 5 of 8
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