High Precision

10 V IC Reference

AD581

Rev. C

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FEATURES

Laser trimmed to high accuracy

10.000 V ±5 mV (L and U models)

Trimmed temperature coefficient

5 ppm/°C maximum, 0°C to 70°C (L model)

10 ppm/°C maximum, −55°C to +125°C (U model)

Excellent long-term stability

25 ppm/1000 hrs (noncumulative)

−10 V reference capability

Low quiescent current: 1.0 mA maximum

10 mA current output capability

3-pin TO-5 package

MIL-STD-883 compliant versions available

FUNCTIONAL BLOCK DIAGRAM

TO-5

BOTTOM VIEW

GND

AD581

Figure 1.

GENERAL DESCRIPTION

The AD581 is a 3-pin, temperature compensated, monolithic,

band gap voltage reference that provides a precise 10.00 V output

from an unregulated input level ranging from 12 V to 30 V.

Laser wafer trimming (LWT) is used to trim both the initial

error at +25°C as well as the temperature coefficient, resulting

in high precision performance previously available only in expen-

sive hybrids or oven regulated modules. The 5 mV initial error

tolerance and 5 ppm/°C guaranteed temperature coefficient of

the AD581L is available in a monolithic voltage reference.

The band gap circuit design used in the AD581 offers several

advantages over classical Zener breakdown diode techniques.

Most important, no external components are required to

achieve full accuracy and significant stability to low power

systems. In addition, total supply current to the device,

including the output buffer amplifier (which can supply up

to 10 mA) is typically 750 μA. The long-term stability of the

band gap design is equivalent to selected Zener reference

diodes.

The AD581 is recommended for use as a reference for 8-, 10-

or 12-bit digital-to-analog converters (DACs) that require an

external precision reference. The device is also ideal for all types

of analog-to-digital converters (ADCs) up to 14-bit accuracy,

either successive approximation or integrating designs, and can

generally offer better performance than that provided by standard

self-contained references.

The AD581J, AD581K, and AD581L are specified for operation

from 0°C to 70°C; the AD581S, AD581T, and AD581U are

specified for the −55°C to +125°C range. All grades are

packaged in a hermetically sealed 3-pin TO-5 metal can.

PRODUCT HIGHLIGHTS

1.

Laser trimming of both initial accuracy and temperature

coefficient results in very low errors over temperature

without the use of external components. The AD581L has

a maximum deviation from 10.000 V of ±7.25 mV from

0°C to 70°C, whereas the AD581U guarantees ±15 mV

maximum total error without external trims from −55°C

to +125°C.

2.

Because the laser trimming is done on the wafer prior to

separation into individual chips, the AD581 is extremely

valuable to hybrid designers for its ease of use, lack of

required external trims, and inherent high performance.

3.

The AD581 can also be operated in a 2-pin Zener mode to

provide a precision −10 V reference with just one external

resistor to the unregulated supply. The performance in this

mode is nearly equal to that of the standard 3-pin confi-

guration.

4.

Advanced circuit design using the band gap concept allows

the AD581 to give full performance with an unregulated

input voltage down to 13 V. With an external resistor, the

device operates with a supply as low as 11.4 V.

5.

The AD581 is available in versions compliant with

MILSTD-883. Refer to the military datasheet for detailed

specifications.