Document Outline
- FEATURES
- GENERAL DESCRIPTION
- FUNCTIONAL BLOCK DIAGRAM
- PRODUCT HIGHLIGHTS
- SPECIFICATIONS
- ABSOLUTE MAXIMUM RATINGS
- PIN CONFIGURATION
- ORDERING GUIDE
- THEORY OF OPERATION
- APPLYING THE AD587
- NOISE PERFORMANCE AND REDUCTION
- TURN-ON TIME
- DYNAMIC PERFORMANCE
- LOAD REGULATION
- TEMPERATURE PERFORMANCE
- NEGATIVE REFERENCE VOLTAGE FROM AN AD587
- USING THE AD587 WITH CONVERTERS
- 10 V Reference with Multiplying CMOS DACs or ADCs
- Precision Current Source
- Precision High Current Supply
- OUTLINE DIMENSIONS
- Revision History
REV. F
AD587
High Precision
10 V Reference
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. 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.
FEATURES
Laser Trimmed to High Accuracy:
10.000 V
5 mV (L and U Grades)
Trimmed Temperature Coefficient:
5 ppm/ C Max (L and U Grades)
Noise Reduction Capability
Low Quiescent Current: 4 mA Max
Output Trim Capability
MIL-STD-883 Compliant Versions Available
FUNCTIONAL BLOCK DIAGRAM
8
2
6
4
5
R
T
R
F
R
I
R
S
AD587
A1
+V
I N
NOISE
REDUCTION
V
OUT
TRIM
GND
NOTE
PINS 1, 3, AND 7 ARE INTERNAL TEST POINTS.
NO CONNECTIONS TO THESE POINTS.
GENERAL DESCRIPTION
The AD587 represents a major advance in state-of-the-art
monolithic voltage references. Using a proprietary ion-implanted
buried Zener diode and laser wafer trimming of high stability
thin-film resistors, the AD587 provides outstanding performance
at low cost.
The AD587 offers much higher performance than most other
10 V references. Because the AD587 uses an industry-standard
pinout, many systems can be upgraded instantly with the AD587.
The buried Zener approach to reference design provides lower
noise and drift than band gap voltage references. The AD587
offers a noise reduction pin that can be used to further reduce
the noise level generated by the buried Zener.
The AD587 is recommended for use as a reference for 8-, 10-, 12-,
14-, or 16-bit DACs that require an external precision reference.
The device is also ideal for successive approximation or integrat-
ing ADCs with up to 14 bits of accuracy and, in general, can
offer better performance than the standard on-chip references.
The AD587J, AD587K, and AD587L are specified for operation
from 0
C to 70C, and the AD587U is specified for 55C to
+125
C operation. All grades are available in 8-lead CERDIP.
The J and K versions are also available in an 8-lead SOIC package
for surface-mount applications, while the J, K, and L grades also
come in an 8-lead PDIP.
PRODUCT HIGHLIGHTS
1. Laser trimming of both initial accuracy and temperature
coefficients results in very low errors over temperature without
the use of external components. The AD587L has a maximum
deviation from 10.000 V of
8.5 mV between 0C and 70C,
and the AD587U guarantees
14 mV maximum total error
between 55
C and +125C.
2. For applications requiring higher precision, an optional fine
trim connection is provided.
3. Any system using an industry-standard pinout 10 V reference
can be upgraded instantly with the AD587.
4. Output noise of the AD587 is very low, typically 4
V p-p.
A noise reduction pin is provided for additional noise filtering
using an external capacitor.
5. The AD587 is available in versions compliant with
MIL-STD-883. Refer to the Analog Devices Military Products
Databook or the current AD587/883B Data Sheet for detailed
specifications.
REV. F
2
AD587SPECIFICATIONS
(T
A
= 25 C, V
IN
= 15 V, unless otherwise noted.)
AD587J
AD587K
AD587L/AD587U
Parameter
Min
Typ
Max
Min
Typ
Max
Min
Typ
Max
Unit
OUTPUT VOLTAGE
9.990
10.010
9.995
10.005 9.995
10.005
V
OUTPUT VOLTAGE DRIFT
1
0
C to 70C
20
10
5
ppm/
C
55
C to +125C
20
10
5
GAIN ADJUSTMENT
+3
+3
+3
%
1
1
1
LINE REGULATION
1
13.5 V
+V
IN
36 V
T
MIN
to T
MAX
100
100
100
V/V
LOAD REGULATION
1
Sourcing 0 mA < I
OUT
< 10 mA
T
MIN
to T
MAX
100
100
100
V/mA
Sourcing 10 mA < I
OUT
< 0 mA
2
T
MIN
to T
MAX
100
100
100
QUIESCENT CURRENT
2
4
2
4
2
4
mA
POWER DISSIPATION
30
30
30
mW
OUTPUT NOISE
0.1 Hz to 10 Hz
4
4
4
V p-p
Spectral Density, 100 Hz
100
100
100
nV/
Hz
LONG-TERM STABILITY
15
15
15
ppm/1000 hr.
SHORT-CIRCUIT
CURRENT-TO-GROUND
30
70
30
70
30
70
mA
SHORT-CIRCUIT
CURRENT-TO-V
IN
30
70
30
70
30
70
mA
TEMPERATURE RANGE
Specified Performance (J, K, L)
0
+70
0
+70
0
+70
C
Operating Performance (J, K, L)
3
40
+85
40
+85
40
+85
Specified Performance (U)
55
+125
55
+125
55
+125
Operating Performance (U)
3
55
+125
55
+125
55
+125
NOTES
1
Specification is guaranteed for all packages and grades. C ERDIP packaged parts are 100% production tested.
2
Load regulation (sinking) specification for SOIC (R) package is
200 V/mA.
3
The operating temperature range is defined as the temperature extremes at which the device will still function. Parts may deviate from their specified performance
outside their specified temperature range.
Specifications subject to change without notice.
REV. F
AD587
3
ABSOLUTE MAXIMUM RATINGS
*
+V
IN
to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 V
Power Dissipation (25
C) . . . . . . . . . . . . . . . . . . . . . 500 mW
Storage Temperature . . . . . . . . . . . . . . . . . . 65
C to +150C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . . 300
C
Package Thermal Resistance
JC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
C/W
JA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
C/W
Output Protection: Output safe for indefinite short to ground
and momentary short to +V
IN
.
*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
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
PIN CONFIGURATION
1
2
3
4
8
7
6
5
AD587
TOP VIEW
(Not to Scale)
TP*
TRIM
V
OUT
TP*
NOISE
REDUCTION
+V
I N
TP*
GND
*TP DENOTES FACTORY TEST POINT.
NO CONNECTIONS SHOULD BE MADE
TO THESE PINS.
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
AD587 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.
ORDERING GUIDE
Initial
Temperature
Temperature
Package
Model
Error
Coefficient
Range
Option
1
AD587JQ
10 mV
20 ppm/
C
0
C to 70C
Q-8
AD587JR
10 mV
20 ppm/
C
0
C to 70C
R-8
AD587JR-REEL
10 mV
20 ppm/
C
0
C to 70C
R-8
AD587JR-REEL7
10 mV
20 ppm/
C
0
C to 70C
R-8
AD587JRZ
2
10 mV
20 ppm/
C
0
C to 70C
R-8
AD587JRZ-REEL
2
10 mV
20 ppm/
C
0
C to 70C
R-8
AD587JRZ-REEL7
2
10 mV
20 ppm/
C
0
C to 70C
R-8
AD587JN
10 mV
20 ppm/
C
0
C to 70C
N-8
AD587JNZ
2
10 mV
20 ppm/
C
0
C to 70C
N-8
AD587KQ
5 mV
10 ppm/
C
0
C to 70C
Q-8
AD587KR
5 mV
10 ppm/
C
0
C to 70C
R-8
AD587KR-REEL
5 mV
10 ppm/
C
0
C to 70C
R-8
AD587KR-REEL7
5 mV
10 ppm/
C
0
C to 70C
R-8
AD587KRZ
2
5 mV
10 ppm/
C
0
C to 70C
R-8
AD587KRZ-REEL
2
5 mV
10 ppm/
C
0
C to 70C
R-8
AD587KRZ-REEL7
2
5 mV
10 ppm/
C
0
C to 70C
R-8
AD587KN
5 mV
10 ppm/
C
0
C to 70C
N-8
AD587LQ
5 mV
5 ppm/
C
0
C to 70C
Q-8
AD587LN
5 mV
5 ppm/
C
0
C to 70C
N-8
AD587UQ
5 mV
5 ppm/
C
55
C to +125C
Q-8
NOTES
1
N = PDIP; Q = CERDIP; R = SOIC.
2
Z = Pb-free part.
REV. F
4
AD587
THEORY OF OPERATION
The AD587 consists of a proprietary buried Zener diode refer-
ence, an amplifier to buffer the output, and several high stability
thin-film resistors as shown in the block diagram in Figure 1.
This design results in a high precision monolithic 10 V output
reference with initial offset of 5 mV or less. The temperature
compensation circuitry provides the device with a temperature
coefficient of under 5 ppm/
C.
8
2
6
4
5
R
T
R
F
R
I
R
S
AD587
A1
+V
I N
NOISE
REDUCTION
V
OUT
TRIM
GND
NOTE
PINS 1, 3 AND 7 ARE INTERNAL TEST POINTS.
NO CONNECTIONS TO THESE POINTS.
Figure 1. Functional Block Diagram
A capacitor can be added at the NOISE REDUCTION pin
(Pin 8) to form a low-pass filter with R
S
to reduce the noise
contribution of the Zener to the circuit.
APPLYING THE AD587
The AD587 is simple to use in virtually all precision reference
applications. When power is applied to Pin 2, and Pin 4 is
grounded, Pin 6 provides a 10 V output. No external components
are required; the degree of desired absolute accuracy is achieved
simply by selecting the required device grade. The AD587 requires
less than 4 mA quiescent current from an operating supply of 15 V.
Fine trimming may be desired to set the output level to exactly
10.000 V (calibrated to a main system reference). System calibra-
tion may also require a reference voltage that is slightly different
from 10.000 V, for example, 10.24 V for binary applications. In
either case, the optional trim circuit shown in Figure 2 can offset
the output by as much as 300 mV with minimal effect on other
device characteristics.
8
2
6
4
GND
5
AD587
V
I N
NOISE
REDUCTION
TRIM
V
O
10k
OUTPUT
+V
I N
C
N
1 F
OPTIONAL
NOISE
REDUCTION
CAPACITOR
Figure 2. Optional Fine Trim Configuration
NOISE PERFORMANCE AND REDUCTION
The noise generated by the AD587 is typically less than 4
V p-p
over the 0.1 Hz to 10 Hz band. Noise in a 1 MHz bandwidth is
approximately 200
V p-p. The dominant source of this noise is
the buried Zener, which contributes approximately 100 nV/
Hz.
In comparison, the op amp's contribution is negligible. Figure 3
shows the 0.1 Hz to 10 Hz noise of a typical AD587. The noise
measurement is made with a band-pass filter made of a 1-pole
high-pass filter with a corner frequency at 0.1 Hz and a 2-pole
low-pass filter with a corner frequency at 12.6 Hz to create a
filter with a 9.922 Hz bandwidth.
Figure 3. 0.1 Hz to 10 Hz Noise
If further noise reduction is desired, an external capacitor may
be added between the NOISE REDUCTION pin and ground,
as shown in Figure 2. This capacitor, combined with the
4 k
R
S
and the Zener resistances, forms a low-pass filter on the
output of the Zener cell. A 1
F capacitor will have a 3 dB point
at 40 Hz, and will reduce the high frequency (to 1 MHz) noise
to about 160
V p-p. Figure 4 shows the 1 MHz noise of a typi-
cal AD587 both with and without a 1
F capacitor.
Figure 4. Effect of 1
F Noise Reduction Capacitor
on Broadband Noise
TURN-ON TIME
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 components
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 5 shows the turn-on characteristics of the AD587.
It shows the settling to be about 60
s to 0.01%. Note the absence
of any thermal tails when the horizontal scale is expanded to
1 ms/cm in Figure 5b.
REV. F
AD587
5
Output turn-on time is modified when an external noise reduc-
tion capacitor is used. When present, this capacitor acts as an
additional load to the internal Zener diode's current source,
resulting in a somewhat longer turn-on time. In the case of a
1
F capacitor, the initial turn-on time is approximately 400 ms
to 0.01% (see Figure 5c).
a. Electrical Turn-On
b. Extended Time Scale
c. Turn-On with 1
F CN
Figure 5. Turn-On Characteristics
DYNAMIC PERFORMANCE
The output buffer amplifier is designed to provide the AD587
with static and dynamic load regulation superior to less complete
references.
Many ADCs and DACs present transient current loads to the
reference, and poor reference response can degrade the converter's
performance.
Figures 6b and 6c display the characteristics of the AD587 output
amplifier driving a 0 mA to 10 mA load.
AD587
V
OUT
7.0V
1k
V
L
10V
0V
Figure 6a. Transient Load Test Circuit
Figure 6b. Large-Scale Transient Response
Figure 6c. Fine Scale Setting for Transient Load
PDF 
ZIP