AD584.PDF

Pin Programmable

Precision Voltage Reference

AD584*

FEATURES

Four Programmable Output Voltages:

10.000 V, 7.500 V, 5.000 V, 2.500 V

Laser-Trimmed to High Accuracies

No External Components Required

Trimmed Temperature Coefficient:

5 ppm/

PIN CONFIGURATIONS

8-Pin TO-99

C max, 0

C to +70

C (AD584L)

C (AD584T)

Zero Output Strobe Terminal Provided

Two Terminal Negative Reference

Capability (5 V & Above)

Output Sources or Sinks Current

Low Quiescent Current: 1.0 mA max

10 mA Current Output Capability

MIL-STD-883 Compliant Versions Available

C max, –55

C to +125

8-Pin DIP

GENERAL DESCRIPTION

The AD584 is an eight-terminal precision voltage reference of-

fering pin-programmable selection of four popular output volt-

ages: 10.000 V, 7.500 V, 5.000 V and 2.500 V. Other output

voltages, above, below or between the four standard outputs, are

available by the addition of external resistors. Input voltage may

vary between 4.5 and 30 volts.

Laser Wafer Trimming (LWT) is used to adjust the pin-pro-

grammable output levels and temperature coefficients, resulting

in the most flexible high precision voltage reference available in

monolithic form.

In addition to the programmable output voltages, the AD584

offers a unique strobe terminal which permits the device to be

turned on or off. When the AD584 is used as a power supply

reference, the supply can be switched off with a single, low-

power signal. In the “off” state the current drain by the AD584

is reduced to about 100 mA. In the “on” state the total supply

current is typically 750 mA including the output buffer amplifier.

The AD584 is recommended for use as a reference for 8-, 10- or

12-bit D/A converters which require an external precision refer-

ence. The device is also ideal for all types of A/D converters of

up to 14-bit accuracy, either successive approximation or inte-

grating designs, and in general can offer better performance

than that provided by standard self-contained references.

The AD584J, K and L are specified for operation from 0°C to

+70°C; the AD584S and T are specified for the –55°C to

+125°C range. All grades are packaged in a hermetically sealed

eight-terminal TO-99 metal can; the AD584 J and K are also

available in an 8-pin plastic DIP.

* Protected by U.S. Patent No. 3,887,863; RE 30,586

PRODUCT HIGHLIGHTS

1. The flexibility of the AD584 eliminates the need to design-

in and inventory several different voltage references. Fur-

thermore one AD584 can serve as several references

simultaneously when buffered properly.

2. Laser trimming of both initial accuracy and temperature co-

efficient results in very low errors over temperature without

the use of external components. The AD584LH has a maxi-

mum deviation from 10.000 volts of ± 7.25 mV from 0°C to

+70°C.

3. The AD584 can be operated in a two-terminal “Zener”

mode at 5 volts output and above. By connecting the input

and the output, the AD584 can be used in this “Zener” con-

figuration as a negative reference.

4. The output of the AD584 is configured to sink or source

currents. This means that small reverse currents can be tol-

erated in circuits using the AD584 without damage to the

reference and without disturbing the output voltage (10 V,

7.5 V and 5 V outputs).

5. The AD584 is available in versions compliant with MIL-

STD-883. Refer to the Analog Devices Military Products

Databook or current AD584/883B data sheet for detailed

specifications.

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

which may result from its use. No license is granted by implication or

otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700

Fax: 617/326-8703

15 ppm/

AD584–SPECIFICATIONS

Model

(@ V IN = +15 V and 25

AD584J

AD584K

AD584L

Min Typ Max

Min Typ Max Units

OUTPUT VOLTAGE TOLERANCE

Maximum Error 1 for Nominal

Outputs of:

10.000 V

6 30

6 10

6 5

7.500 V

5.000 V

6 15

6 6

6 3

2.500 V

7.5

3.5

2.5 mV

OUTPUT VOLTAGE CHANGE

Maximum Deviation from +25°C

Value, T MIN to T MAX 2

10.000 V, 7.500 V, 5.000 V Outputs

ppm/°C

2.500 V Output

ppm/

Differential Temperature

Coefficients Between Outputs

ppm/

QUIESCENT CURRENT

0.75 1.0

Temperature Variation

1.5

mA/°C

TURN-ON SETTLING TIME TO 0.1%

200

NOISE

(0.1 Hz to 10 Hz)

V p-p

LONG-TERM STABILITY

ppm/1000 Hrs

SHORT-CIRCUIT CURRENT

LINE REGULATION (No Load)

15 V £ V IN £ 30 V

0.002

0.002 %/V

(V OUT +2.5 V)

V IN

15 V

0.005

0.005 %/V

LOAD REGULATION

0 £ I OUT £ 5 mA, All Outputs

ppm/mA

OUTPUT CURRENT

V IN

Source T MIN to T MAX

Sink T MIN to T MAX

TEMPERATURE RANGE

Operating

+70

Storage

–65

+175 –65

+175

°C

PACKAGE OPTION 3

TO-99 (H-08A)

AD584JH

AD584KH

AD584LH

Plastic (N-8)

AD584JN

AD584KN

NOTES

1 At Pin 1.

2 Calculated as average over the operating temperature range.

3 H = Hermetic Metal Can; N = Plastic DIP.

Specifications subject to change without notice.

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.

METALIZATION PHOTOGRAPH

Dimensions shown in inches and (mm).

ABSOLUTE MAXIMUM RATINGS

Input Voltage V IN to Ground . . . . . . . . . . . . . . . . . . . . . . . 40 V

Power Dissipation @ +25°C . . . . . . . . . . . . . . . . . . . . 600 mW

Operating Junction Temperature Range . . . . –55°C to +125°C

Lead Temperature (Soldering 10 sec) . . . . . . . . . . . . . +300°C

Thermal Resistance

Junction-to-Ambient (H-08A) . . . . . . . . . . . . . . . . 150°C/W

–2–

REV. A

V OUT +2.5 V

Source @ +25°C

AD584

Model

AD584S

AD584T

Min Typ

Max

Min Typ Max

Units

OUTPUT VOLTAGE TOLERANCE

Maximum Error 1 for Nominal

Outputs of:

10.000 V

6 30

6 10

7.500 V

6 20

6 8

5.000 V

6 15

± 6

2.500 V

6 7.5

6 3.5

OUTPUT VOLTAGE CHANGE

Maximum Deviation from +25

Value, T MIN to T MAX 2

10.000 V, 7.500 V, 5.000 V Outputs

ppm/

2.500 V Output

ppm/

Differential Temperature

Coefficients Between Outputs

ppm/

QUIESCENT CURRENT

0.75 1.0

Temperature Variation

1.5

mA/°C

TURN-ON SETTLING TIME TO 0.1%

200

NOISE

(0.1 Hz to 10 Hz)

V p-p

LONG-TERM STABILITY

ppm/1000 Hrs

SHORT-CIRCUIT CURRENT

LINE REGULATION (No Load)

15 V

V IN

30 V

0.002

%/V

(V OUT +2.5 V)

V IN

15 V

0.005

%/V

LOAD REGULATION

0 £ I OUT £ 5 mA, All Outputs

ppm/mA

OUTPUT CURRENT

V IN

Source T MIN to T MAX

Sink T MIN to T MAX

TEMPERATURE RANGE

Operating

–55

+125

–55

+125

Storage

–65

+175

–65

+175

PACKAGE OPTION

TO-99 (H-08A)

AD584SH

AD584TH

NOTES

1 At Pin 1.

2 Calculated as average over the operating temperature range.

Specifications subject to change without notice.

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.

REV. A

–3–

V OUT +2.5 V

Source @ +25

AD584

APPLYING THE AD584

With power applied to Pins 8 and 4 and all other pins open, the

AD584 will produce a buffered nominal 10.0 V output between

Pins 1 and 4 (see Figure 1). The stabilized output voltage may

be reduced to 7.5 V, 5.0 V or 2.5 V by connecting the program-

ming pins as follows:

range will be about 20 V even for large values of R1. R2 should

not be omitted; its value should be chosen to limit the output to

a value which can be tolerated by the load circuits. If R2 is zero,

adjusting R1 to its lower limit will result in a loss of control over

the output voltage. If precision voltages are required to be set at

levels other than the standard outputs, the 20% absolute toler-

ance in the internal resistor ladder must be accounted for.

Alternatively, the output voltage can be raised by loading the

2.5 V tap with R3 alone. The output voltage can be lowered by

connecting R4 alone. Either of these resistors can be a fixed

resistor selected by test or an adjustable resistor. In all cases the

resistors should have a low temperature coefficient to match the

AD584 internal resistors, which have a negative T.C. less than

60 ppm/°C. If both R3 and R4 are used, these resistors should

have matched temperature coefficients.

When only small adjustments or trims are required, the circuit

of Figure 2 offers better resolution over a limited trim range.

The circuit can be programmed to 5.0 V, 7.5 V or 10 V and ad-

justed by means of R1 over a range of about ± 200 mV. To trim

the 2.5 V output option, R2 (Figure 2) can be reconnected to

the bandgap reference (Pin 6). In this configuration, the adjust-

ment should be limited to ± 100 mV in order to avoid affecting

the performance of the AD584.

Output

Voltage

Pin Programming

7.5 V

Join the 2.5 V and 5.0 V pins (2) and (3)

5.0 V

Connect the 5.0 V pin (2) to the output pin (1).

2.5 V

Connect the 2.5 V pin (3) to the output pin (1).

The options shown above are available without the use of any

additional components. Multiple outputs using only one

AD584, are also possible by simply buffering each voltage pro-

gramming pin with a unity-gain noninverting op amp.

Figure 2. Output Trimming

Figure 1. Variable Output Options

The AD584 can also be programmed over a wide range of out-

put voltages, including voltages greater than 10 V, by the ad-

dition of one or more external resistors. Figure 1 illustrates the

general adjustment procedure, with approximate values given

for the internal resistors of the AD584. The AD584 may be

modeled as an op amp with a noninverting feedback connection,

driven by a high stability 1.215 volt bandgap reference (see Fig-

ure 3 for schematic).

When the feedback ratio is adjusted with external resistors, the

output amplifier can be made to multiply the reference voltage

by almost any convenient amount, making popular outputs of

10.24 V, 5.12 V, 2.56 V or 6.3 V easy to obtain. The most

general adjustment (which gives the greatest range and poorest

resolution) uses R1 and R2 alone (see Figure 1). As R1 is ad-

justed to its upper limit the 2.5 V Pin 3 will be connected to the

output, which will reduce to 2.5 V. As R1 is adjusted to its

lower limit, the output voltage will rise to a value limited by R2.

For example, if R2 is about 6 kW, the upper limit of the output

Figure 3. Schematic Diagram

–4–

REV. A

AD584

PERFORMANCE OVER TEMPERATURE

Each AD584 is tested at three temperatures over the –55°C to

+125°C range to ensure that each device falls within the Maxi-

mum Error Band (see Figure 4) specified for a particular grade

(i.e., S and T grades); three-point measurement guarantees per-

formance within the error band from 0°C to +70°C (i.e., J, K,

or L grades). The error band guaranteed for the AD584 is the

maximum deviation from the initial value at +25°C. Thus, given

the grade of the AD584, the designer can easily determine the

maximum total error from initial tolerance plus temperature

variation. For example, for the AD584T, the initial tolerance is

± l0 mV and the error band is ± 15 mV. Hence, the unit is guar-

anteed to be 10.000 volts ± 25 mV from –55°C to +125°C.

needed, and yet respond quickly when the power is turned on

for operation. Figure 6 displays the turn-on characteristic of the

AD584. Figure 6a is generated from cold-start operation and

represents the true turn-on waveform after an extended period

with the supplies off. The figure shows both the coarse and fine

transient characteristics of the device; the total settling time to

within ± 10 millivolt is about 180 ms, and there is no long ther-

mal tail appearing after the point.

Figure 6. Output Settling Characteristic

Figure 4. Typical Temperature Characteristic

NOISE FILTERING

The bandwidth of the output amplifier in the AD584 can be re-

duced to filter the output noise. A capacitor ranging between

0.01 mF and 0.1 mF connected between the Cap and V BG termi-

nals will further reduce the wideband and feedthrough noise in

the output of the AD584, as shown in Figure 8. However, this

will tend to increase the turn-on settling time of the device so

ample warm-up time should be allowed.

OUTPUT CURRENT CHARACTERISTICS

The AD584 has the capability to either source or sink current

and provide good load regulation in either direction, although it

has better characteristics in the source mode (positive current

into the load). The circuit is protected for shorts to either posi-

tive supply or ground. The output voltage vs. output current

characteristics of the device is shown in Figure 5. Source current

is displayed as negative current in the figure; sink current is

positive. Note that the short circuit current (i.e., zero volts out-

put) is about 28 mA; when shorted to +15 volts, the sink cur-

rent goes to about 20 mA.

Figure 7. Additional Noise Filtering with an External

Capacitor

Figure 5. AD584 Output Voltage vs. Sink and Source

Current

DYNAMIC PERFORMANCE

Many low power instrument manufacturers are becoming in-

creasingly concerned with the turn-on characteristics of the

components being used in their systems. Fast turn-on compo-

nents often enable the end user to keep power off when not

Figure 8. Spectral Noise Density and Total rms Noise vs.

Frequency

REV. A

–5–

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