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. No license is granted by implication or otherwise

under any patent or patent rights of Analog Devices.

a

ADR420/ADR421/ADR423/ADR425

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

© Analog Devices, Inc., 2002

Ultraprecision Low Noise, 2.048 V/2.500 V/

PIN CONFIGURATION

Surface-Mount Packages

8-Lead SOIC

8-Lead Mini_SOIC

TOP VIEW

(Not to Scale)

8

7

6

5

1

2

3

4

NIC = NO INTERNAL CONNECTION

TP = TEST PIN (DO NOT CONNECT)

TP

NIC

GND

TP

NIC

TRIM

ADR42x

FEATURES

Low Noise (0.1 Hz to 10 Hz)

ADR420: 1.75

V p-p

ADR421: 1.75

V p-p

ADR423: 2.0

V p-p

ADR425: 3.4

V p-p

Low Temperature Coefficient: 3 ppm/ C

Long-Term Stability: 50 ppm/1000 Hours

Load Regulation: 70 ppm/mA

Line Regulation: 35 ppm/V

Low Hysteresis: 40 ppm Typical

Wide Operating Range

ADR420: 4 V to 18 V

ADR421: 4.5 V to 18 V

ADR423: 5 V to 18 V

ADR425: 7 V to 18 V

Quiescent Current: 0.5 mA Maximum

High Output Current: 10 mA

Wide Temperature Range: –40 C to +125 C

APPLICATIONS

Precision Data Acquisition Systems

High-Resolution Converters

Battery-Powered Instrumentation

Portable Medical Instruments

Industrial Process Control Systems

Precision Instruments

Optical Network Control Circuits

GENERAL DESCRIPTION

The ADR42x series are ultraprecision second-generation XFET

voltage references featuring low noise, high accuracy, and excellent

long-term stability in a SOIC and Mini_SOIC footprints. Patented

temperature drift curvature correction technique and XFET (eXtra

implanted junction FET) technology minimize nonlinearity of the

voltage change with temperature. The XFET architecture offers

superior accuracy and thermal hysteresis to the bandgap

references. It also operates at lower power and lower supply

headroom than the Buried Zener references.

The superb noise, stable, and accurate characteristics of ADR42x

make them ideal for precision conversion applications such as

optical network and medical equipment. The ADR42x trim

terminal can also be used to adjust the output voltage over a

±0.5% range without compromising any other performance. The

ADR42x series voltage references offer two electrical grades and

are specified over the extended industrial temperature range

of –40

°C to +125°C. Devices are available in 8-lead SOIC-8 or

30% smaller 8-lead Mini_SOIC-8 packages.

XFET is a registered trademark of Analog Devices, Inc.

Table I. ADR42x Products

Output

Initial

ADR420

Voltage

Accuracy

Tempco

Products

mV

%

ppm/

ADR420

2.048

1, 3

0.05, 0.15

3, 10

ADR421

2.50

1, 3

0.04, 0.12

3, 10

ADR423

3.00

1.5, 4

0.04, 0.12

3, 10

ADR425

5.00

2, 6

0.04, 0.12

3, 10