AD587JN ,High Precision 10 V ReferenceHigh Precisiona10 V ReferenceAD587FUNCTIONAL BLOCK DIAGRAM
AD587JNZ ,High Precision 10 V Referenceapplications requiring higher precision, an optional fine10 V references. Because the AD587 uses an ..
AD587JNZ ,High Precision 10 V ReferenceSPECIFICATIONS (T = 25C, V = 15 V, unless otherwise noted.)A IN AD587J AD5 ..
AD587JQ ,High Precision 10 V Referencespecifications.the standard on-chip references.The AD587J, K and L are specified for operation from ..
AD587JR ,High Precision 10 V ReferenceSPECIFICATIONSA INDIE LAYOUT AD587JCHIPSParameter Min Typ Max UnitsOutput Voltage 9.990 10.010 VG ..
AD587JR. ,High Precision 10 V Referencespecifications are tested at the die level for AD587JCHIPS. These die are probed at +25
AD587JN-AD587JQ-AD587JR-AD587JR.-AD587KN-AD587KQ-AD587KR-AD587LN-AD587LQ-AD587SQ-AD587TQ-AD587UQ
High Precision 10 V Reference
FUNCTIONAL BLOCK DIAGRAM
+VIN
NOISE
REDUCTION
VOUT
TRIM
GND
NOTE:
PINS 1,3, AND 7 ARE INTERNAL TEST POINTS.
NO CONNECTIONS TO THESE POINTS.REV.D
High Precision
10 V Reference
FEATURES
Laser Trimmed to High Accuracy:
10.000 V 65 mV (L and U Grades)
Trimmed Temperature Coefficient:
5 ppm/8C max, (L and U Grades)
Noise Reduction Capability
Low Quiescent Current: 4 mA max
Output Trim Capability
MIL-STD-883 Compliant Versions Available
PRODUCT HIGHLIGHTSLaser trimming of both initial accuracy and temperature
coefficients results in very low errors over temperature with-
out the use of external components. The AD587L has a
maximum deviation from 10.000 V of –8.5 mV between 0°C
and +70°C, and the AD587U guarantees –14 mV maximum
total error between –55°C and +125°C.For applications requiring higher precision, an optional fine
trim connection is provided.Any system using an industry standard pinout 10 volt refer-
ence can be upgraded instantly with the AD587.Output noise of the AD587 is very low, typically 4 mV p-p. A
noise reduction pin is provided for additional noise filtering
using an external capacitor.The AD587 is available in versions compliant with MIL-
STD-883. Refer to the Analog Devices Military Products
Databook or current AD587/883B data sheet for detailed
specifications.
PRODUCT DESCRIPTIONThe AD587 represents a major advance in the state-of-the-art in
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 perfor-
mance 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 pro-
vides lower noise and drift than bandgap voltage references. The
AD587 offers a noise reduction pin which 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 D/A converters which require an external
precision reference. The device is also ideal for successive
approximation or integrating A/D converters with up to 14 bits
of accuracy and, in general, can offer better performance than
the standard on-chip references.
The AD587J, K and L are specified for operation from 0°C to
+70°C, and the AD587S, T and U are specified for –55°C to
+125°C operation. All grades are available in 8-pin cerdip. The
J and K versions are also available in an 8-pin Small Outline IC
(SOIC) package for surface mount applications, while the J, K,
and L grades also come in an 8-pin plastic package.
AD587–SPECIFICATIONSGAIN ADJUSTMENT
LINE REGULATION
LOAD REGULATION
TEMPERATURE RANGE
NOTESSpec is guaranteed for all packages and grades. Cerdip packaged parts are 100% production test.Load Regulation (Sinking) specification for SOIC (R) package is –200 mV/mA.The operating temperature ranged is defined as the temperatures 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.
(TA = +258C, VIN = +15 V unless otherwise noted)
ORDERING GUIDENOTESFor details on grade and package offerings screened in accordance with MIL-STD-883, refer to the
Analog Devices Military Products Databook or current AD587/883B data sheet.N = Plastic DIP; Q = Cerdip; SO = SOIC.
ABSOLUTE MAXIMUM RATINGS*VIN to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 V
Power Dissipation (+25°C) . . . . . . . . . . . . . . . . . . . . .500 mW
Storage Temperature . . . . . . . . . . . . . . . . . . .–65°C to +150°C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . .+300°C
Package Thermal ResistanceJC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22°C/WJA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110°C/W
Output Protection: Output safe for indefinite short to ground and
momentary short to VIN.
*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.
DIE SPECIFICATIONS
The following specifications are tested at the die level for AD587JCHIPS. These die are probed at +25°C only.
(TA = +25°C, VIN = +15 V unless otherwise noted)NOTESBoth VOUT pads should be connected to the output.Sense and force grounds must be tied together.
Die Thickness: The standard thickness of Analog Devices Bipolar dice is 24 mils – 2 mils.
Die Dimensions: The dimensions given have a tolerance of –2 mils.
Backing: The standard backside surface is silicon (not plated). Analog Devices does not recommendgold-backed dice for most applications.
Edges: A diamond saw is used to separate wafers into dice thus providing perpendicular edges half-way through the die.
In contrast to scribed dice, this technique provides a more uniform die shape and size . The perpen-
dicular edges facilitate handling (such as tweezer pick-up) while the uniform shape and size simplifies
substrate design and die attach.
Top Surface: The standard top surface of the die is covered by a layer of glassivation . All areas arecovered except bonding pads and scribe lines.
Surface Metalization: The metalization to Analog Devices bipolar dice is aluminum. Minimumthickness is 10,000Å.
Bonding Pads: All bonding pads have a minimum size of 4 mils by 4 mils. The passivation windows have 3.5 mils by 3.5 mils minimum.
DIE LAYOUT
PIN CONFIGURATIONDie Size: 0.081 · 0.060 Inches
AD587
THEORY OF OPERATIONThe 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.
+VIN
NOISE
REDUCTION
VOUT
TRIM
GND
NOTE:
PINS 1,3, AND 7 ARE INTERNAL TEST POINTS.
NO CONNECTIONS TO THESE POINTS.Figure 1.AD587 Functional Block Diagram
A capacitor can be added at the NOISE REDUCTION pin (Pin
8) to form a low-pass filter with RS to reduce the noise contribu-
tion of the Zener to the circuit.
APPLYING THE AD587The 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 compo-
nents 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 oper-
ating 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 cali-
bration may also require a reference voltage that is slightly differ-
ent 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, if desired, with mini-
mal effect on other device characteristics.
OUTPUT
+VIN
1µF
OPTIONAL
NOISE
REDUCTION
CAPACITORFigure 2.Optional Fine Trim Configuration
NOISE PERFORMANCE AND REDUCTIONThe noise generated by the AD587 is typically less than 4 mV
p-p over the 0.1 Hz to 10 Hz band. Noise in a 1 MHz band-
width is approximately 200 mV 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 negli-
gible. Figure 3 shows the 0.1 Hz to 10 Hz noise of a typical
AD587. The noise measurement is made with a bandpass 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 kW RS
and the Zener resistances, form a low-pass filter on the output
of the Zener cell. A 1 mF capacitor will have a 3 dB point at
40 Hz, and it will reduce the high frequency (to 1 MHz) noise
to about 160 mV p-p. Figure 4 shows the 1 MHz noise of a typi-
cal AD587 both with and without a 1 mF capacitor.
Figure 4.Effect of 1 mF Noise Reduction Capacitor on
Broadband Noise
TURN-ON TIMEUpon 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
DYNAMIC PERFORMANCEThe output buffer amplifier is designed to provide the AD587
with static and dynamic load regulation superior to less com-
plete references.
Many A/D and D/A converters present transient current loads
to the reference, and poor reference response can degrade the
converter’s performance.
Figure 6 displays the characteristics of the AD587 output ampli-
fier driving a 0 mA to 10 mA load.
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, re-
sulting in a somewhat longer turn-on time. In the case of a 1 mF
capacitor, the initial turn-on time is approximately 400 ms to
0.01% (see Figure 5c).Electrical Turn-OnExtended Time ScaleTurn-On with 1 mF CN
Figure 5.Turn-On Characteristics
Figure 6a.Transient Load Test Circuit
Figure 6b.Large-Scale Transient Response
Figure 6c.Fine Scale Settling for Transient Load
VOUT
AD587In some applications, a varying load may be both resistive and
capacitive in nature, or the load may be connected to the
AD587 by a long capacitive cable.
Figure 7 displays the output amplifier characteristics driving a
1000 pF, 0 mA to 10 mA load.
VOUTFigure 7a.Capacitive Load Transient /Response Test Circuit
Figure 7b.Output Response with Capacitive Load
LOAD REGULATIONThe AD587 has excellent load regulation characteristics. Figure
8 shows that varying the load several mA changes the output by
only a few mV.
Figure 8.Typical Load Regulation Characteristics
TEMPERATURE PERFORMANCESome confusion exists in the area of defining and specifying ref-
erence voltage error over temperature. Historically, references
have been characterized using a maximum deviation per degree
Centrigrade; i.e., ppm/°C. However, because of nonlinearities in
temperature characteristics which originated in standard Zener
references (such as “S” type characteristics), most manufactur-
ers have begun to use a maximum limit error band approach to
specify devices. This technique involves the measurement of the
output at three or more different temperatures to specify an out-
put voltage error band.
Figure 9 shows the typical output voltage drift for the AD587L
and illustrates the test methodology. The box in Figure 9 is
bounded on the sides by thc operating temperature extremes,
and on the top and the bottom by the maximum and minimum
output voltages measured over the operating temperature range.
The slope of the diagonal drawn from the lower left to the upper
right corner of the box determines the performance grade of the
device.
Figure 9.Typical AD587L Temperature Drift
Each AD587J, K, L grade unit is tested at 0°C, +25°C and
+70°C. Each AD587S, T, and U grade unit is tested at –55°C,
+25°C and +125°C. This approach ensures that the variations
of output voltage that occur as the temperature changes within
the specified range will be contained within a box whose diago-
nal has a slope equal to the maximum specified drift. The posi-
tion of the box on the vertical scale will change from device to
device as initial error and the shape of the curve vary. The maxi-
mum height of the box for the appropriate temperature range
and device grade is shown in Figure 10. Duplication of these
results requires a combination of high accuracy and stable
temperature control in a test system. Evaluation of the AD587
will produce a curve similar to that in Figure 9, but output
readings may vary depending on the test methods and equip-
ment utilized.
