ANALOG DEVICES ADR420, ADR421, ADR423, ADR425 Service Manual

TOP VIEW

(Not to Scale)

8

7

6

5

1

2

3

4

NIC = NO INTERNAL CONNECTION
TP = TEST PIN (DO NOT CONNECT)

TP

V

IN

NIC

GND

TP

NIC

V

OUT

TRIM

ADR42x

查询ADR420供应商

Ultraprecision Low Noise, 2.048 V/2.500 V/

a

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

3.00 V/5.00 V XFET
ADR420/ADR421/ADR423/ADR425

PIN CONFIGURATION

Surface-Mount Packages

®

Voltage References

8-Lead SOIC

8-Lead Mini_SOIC

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.

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.

Table I. ADR42x Products

Output Initial
ADR420 Voltage Accuracy Tempco
Products V

O

mV % ppm/°C

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

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © Analog Devices, Inc., 2002

ADR42x–SPECIFICATIONS

ADR420 ELECTRICAL SPECIFICATIONS

(@ VIN = 5.0 V to 15.0 V, TA = 25C, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

Output Voltage A Grade V
Initial Accuracy V

O

OERR

2.045 2.048 2.051 V
–3 +3 mV

–0.15 +0.15 %
Output Voltage B Grade V
Initial Accuracy V

O

OERR

2.047 2.048 2.049 V

–1 +1 mV

–0.05 +0.05 %
Temperature Coefficient A Grade TCV

O

–40°C < TA < +125°C 2 10 ppm/°C

B Grade 1 3 ppm/°C

Supply Voltage Headroom V
Line Regulation ∆V

Load Regulation ∆V

Quiescent Current I

Voltage Noise e
Voltage Noise Density e
Turn-On Settling Time t
Long-Term Stability ∆V
Output Voltage Hysteresis V
Ripple Rejection Ratio RRR f
Short Circuit to GND I

Specifications subject to change without notice.

– V

IN

O

/∆V

O

IN

/∆I

O

LOAD

IN

p-p 0.1 Hz to 10 Hz 1.75 µV p-p

N

N

R

O

O_HYS

SC

VIN = 5 V to 18 V 10 35 ppm/V
–40°C < T
I

LOAD

–40°C < T

< +125°C

A

= 0 mA to 10 mA 70 ppm/mA

< +125°C

A

No Load 390 500 µA
–40°C < T

< +125°C 600 µA

A

1 kHz 60 nV/√Hz

1,000 Hours 50 ppm

= 10 kHz 75 dB

IN

2V

10 µs

40 ppm

27 mA

ADR421 ELECTRICAL SPECIFICATIONS

(@ VIN = 5.0 V to 15.0 V, TA = 25C, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

Output Voltage A Grade V
Initial Accuracy V

O

OERR

2.497 2.500 2.503 V
–3 +3 mV

–0.12 +0.12 %
Output Voltage B Grade V
Initial Accuracy V

O

OERR

2.499 2.500 2.501 V

–1 +1 mV

–0.04 +0.04 %
Temperature Coefficient A Grade TCV

O

–40°C < TA < +125°C 2 10 ppm/°C

B Grade 1 3 ppm/°C

Supply Voltage Headroom V
Line Regulation ∆V

Load Regulation ∆V

Quiescent Current I

Voltage Noise e
Voltage Noise Density e
Turn-On Settling Time t
Long-Term Stability ∆V
Output Voltage Hysteresis V

– V

IN

O

/∆V

O

IN

/∆I

O

LOAD

IN

p-p 0.1 Hz to 10 Hz 1.75 µV p-p

N

N

R

O

O_HYS

Ripple Rejection Ratio RRR f
Short Circuit to GND I

Specifications subject to change without notice.

SC

VIN = 5 V to 18 V 10 35 ppm/V
–40°C < T
I

LOAD

–40°C < T

< +125°C

A

= 0 mA to 10 mA 70 ppm/mA

< +125°C

A

No Load 390 500 µA
–40°C < T

< +125°C 600 µA

A

1 kHz 80 nV/√Hz

1,000 Hours 50 ppm

= 10 kHz 75 dB

IN

2V

10 µs

40 ppm

27 mA

–2–

REV. B

ADR420/ADR421/ADR423/ADR425

ADR423 ELECTRICAL SPECIFICATIONS

(@ VIN = 5.0 V to 15.0 V, TA = 25C, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

Output Voltage A Grade V
Initial Accuracy V

O

OERR

2.996 3.000 3.004 V
–4 +4 mV

–0.13 +0.13 %
Output Voltage B Grade V
Initial Accuracy V

O

OERR

2.9985 3.000 3.0015 V

–1.5 +1.5 mV

–0.04 +0.04 %
Temperature Coefficient A Grade TCV

O

–40°C < TA < +125°C 2 10 ppm/°C

B Grade 1 3 ppm/°C

Supply Voltage Headroom V
Line Regulation ∆V

Load Regulation ∆V

Quiescent Current I

Voltage Noise e
Voltage Noise Density e
Turn-On Settling Time t
Long-Term Stability ∆V
Output Voltage Hysteresis V

− V

IN

O

/∆V

O

IN

/∆I

O

LOAD

IN

p-p 0.1 Hz to 10 Hz 2 µV p-p

N

N

R

O

O_HYS

Ripple Rejection Ratio RRR f
Short Circuit to GND I

Specifications subject to change without notice.

SC

VIN = 5 V to 18 V 10 35 ppm/V
–40°C < T
I

LOAD

–40°C < T

< +125°C

A

= 0 mA to 10 mA 70 ppm/mA

< +125°C

A

No Load 390 500 µA
–40°C < T

< +125°C 600 µA

A

1 kHz 90 nV/√Hz

1,000 Hours 50 ppm

= 10 kHz 75 dB

IN

2V

10 µs

40 ppm

27 mA

ADR425 ELECTRICAL SPECIFICATIONS

(@ VIN = 7.0 V to 15.0 V, TA = 25C, unless otherwise noted.)

Parameter Symbol Conditions Min Typ Max Unit

Output Voltage A Grade V
Initial Accuracy V

O

OERR

4.994 5.000 5.006 V
–6 +6 mV

–0.12 +0.12 %
Output Voltage B Grade V
Initial Accuracy V

O

OERR

4.998 5.000 5.002 V

–2 +2 mV

–0.04 +0.04 %
Temperature Coefficient A Grade TCV

O

–40°C < TA < +125°C 2 10 ppm/°C

B Grade 1 3 ppm/°C

Supply Voltage Headroom V
Line Regulation ∆V

Load Regulation ∆V

Quiescent Current I

Voltage Noise e
Voltage Noise Density e
Turn-On Settling Time t
Long-Term Stability ∆V
Output Voltage Hysteresis V

– V

IN

O

/∆V

O

IN

/∆I

O

LOAD

IN

p-p 0.1 Hz to 10 Hz 3.4 µV p-p

N

N

R

O

O_HYS

Ripple Rejection Ratio RRR f
Short Circuit to GND I

Specifications subject to change without notice.

SC

VIN = 7 V to 18 V 10 35 ppm/V
–40°C < T
I

LOAD

–40°C < T

< +125°C

A

= 0 mA to 10 mA 70 ppm/mA

< +125°C

A

No Load 390 500 µA
–40°C < T

< +125°C 600 µA

A

1 kHz 110 nV/√Hz

1,000 Hours 50 ppm

= 10 kHz 75 dB

IN

2V

10 µs

40 ppm

27 mA

REV. B

–3–

A

WARNING!

ESD SENSITIVE DEVICE

DR420/ADR421/ADR423/ADR425

ABSOLUTE MAXIMUM RATINGS

*

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 V

Output Short-Circuit Duration to GND . . . . . . . . . Indefinite

Storage Temperature Range

R, RM Packages . . . . . . . . . . . . . . . . . . . . –65°C to +150°C

Operating Temperature Range

ADR42x . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +125°C

Junction Temperature Range

R, RM Packages . . . . . . . . . . . . . . . . . . . . –65°C to +150°C

Lead Temperature Range (Soldering, 60 sec) . . . . . . . 300°C

*Absolute maximum ratings apply at 25°C, unless otherwise noted.

PIN CONFIGURATIONS

SOIC-8

1

TP

ADR42x

2

V

IN

NIC

3

4

GND

NIC = NO INTERNAL CONNECTION
TP = TEST PIN (DO NOT CONNECT)

8

TP

7

NIC

6

V

OUT

TRIM

5

Mini_SOIC-8

1

TP

ADR42x

2

V

IN

3

NIC

4

GND

NIC = NO INTERNAL CONNECTION
TP = TEST PIN (DO NOT CONNECT)

8

TP

7

NIC

6

V

OUT

TRIM

5

ORDERING GUIDE

PIN FUNCTION DESCRIPTIONS

Pin Mnemonic Description

1, 8 TP Test Pin. There are actual connections in TP

pins but they are reserved for factory testing
purposes. Users should not connect any­thing to TP pins, otherwise the device may
not function properly.

2V

IN

Input Voltage

3, 7 NIC No Internal Connect. NICs have no internal

connections.
4 GND Ground Pin = 0 V
5 TRIM Trim Terminal. It can be used to adjust the

output voltage over a ±0.5% range without

affecting the temperature coefficient.
6V

OUT

Package Type θ

Output Voltage

*

JA

Unit

8-Lead Mini_SOIC (RM) 190 °C/W
8-Lead SOIC (R) 130 °C/W

*θJA is specified for the worst-case conditions, i.e., θJA is specified for device soldered

in circuit board for surface-mount packages.

Output Initial Temperature Number of

Temperature

Voltage Accuracy Coefficient Package Package Top Parts per Range

Model V

O

mV % ppm/°C Description Option Mark Reel °C

ADR420AR 2.048 3 0.15 10 SOIC SO-8 ADR420 98 –40 to +125
ADR420AR-Reel7 2.048 3 0.15 10 SOIC SO-8 ADR420 3,000 –40 to +125
ADR420BR 2.048 1 0.05 3 SOIC SO-8 ADR420 98 –40 to +125
ADR420BR-Reel7 2.048 1 0.05 3 SOIC SO-8 ADR420 3,000 –40 to +125
ADR420ARM-Reel7 2.048 3 0.15 10 Mini_SOIC RM-8 R4A 1,000 –40 to +125

ADR421AR 2.50 3 0.12 10 SOIC SO-8 ADR421 98 –40 to +125
ADR421AR-Reel7 2.50 3 0.12 10 SOIC SO-8 ADR421 3,000 –40 to +125
ADR421BR 2.50 1 0.04 3 SOIC SO-8 ADR421 98 –40 to +125
ADR421BR-Reel7 2.50 1 0.04 3 SOIC SO-8 ADR421 3,000 –40 to +125
ADR421ARM-Reel7 2.50 3 0.12 10 Mini_SOIC RM-8 R5A 1,000 –40 to +125

ADR423AR 3.00 4 0.13 10 SOIC SO-8 ADR423 98 –40 to +125
ADR423AR-Reel7 3.00 4 0.13 10 SOIC SO-8 ADR423 3,000 –40 to +125
ADR423BR 3.00 1.5 0.04 3 SOIC SO-8 ADR423 98 –40 to +125
ADR423BR-Reel7 3.00 1.5 0.04 3 SOIC SO-8 ADR423 3,000 –40 to +125
ADR423ARM-Reel7 3.00 4 0.13 10 Mini_SOIC RM-8 1,000 –40 to +125

ADR425AR 5.00 6 0.12 10 SOIC SO-8 ADR425 98 –40 to +125
ADR425AR-Reel7 5.00 6 0.12 10 SOIC SO-8 ADR425 3,000 –40 to +125
ADR425BR 5.00 2 0.04 3 SOIC SO-8 ADR425 98 –40 to +125
ADR425BR-Reel7 5.00 2 0.04 3 SOIC SO-8 ADR425 3,000 –40 to +125
ADR425ARM-Reel7 5.00 6 0.12 10 Mini_SOIC RM-8 R7A 1,000 –40 to +125

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 AD42x 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.

–4–

REV. B

ADR420/ADR421/ADR423/ADR425

PARAMETER DEFINITIONS
Temperature Coefficient

The change of output voltage over the operating temperature
range and normalized by the output voltage at 25°C, expressed
in ppm/°C. The equation follows:

TCV ppm C

O

/

=

°

()

VCTT

()– ()

21

OO

°×

25

()(– )

O

21

6

×

10

VT VT

where

V

(25°C) = VO at 25°C

O

V

(T1) = VO at Temperature 1

O

V

(T2) = VO at Temperature 2.

O

Line Regulation

The change in output voltage due to a specified change in input
voltage. It includes the effects of self-heating. Line regulation is
expressed in either percent per volt, parts-per-million per volt,
or microvolts per volt change in input voltage

Load Regulation

The change in output voltage due to a specified change in load
current. It includes the effects of self-heating. Load regulation is
expressed in either microvolts per milliampere, parts-per-million
per milliampere, or ohms of dc output resistance.

Long-Term Stability

Typical shift of output voltage at 25°C on a sample of parts
subjected to operation life test of 1000 hours at 125°C:

∆∆VVt Vt

=

()– ()

OO O

V ppm

()

O

01

Vt Vt

()– ()

OO

01

=×

Vt

()

O

0

10

6

where

V

(t0) = VO at 25°C at Time 0

O

V

(t1) = VO at 25°C after 1,000 hours operation at 125°C.

O

Thermal Hysteresis

Thermal hysteresis is defined as the change of output voltage
after the device is cycled through temperature from +25°C to
–40°C to +125°C and back to +25°C. This is a typical value
from a sample of parts put through such a cycle.

VVCV

__

O HYS O O TC

V ppm

_

O HYS

()

()–

=°

25

VCV

()–

°

25

OOTC

=

VC

()

O

25

_

°

×

10

6

where

V

(25°C) = VO at 25°C

O

V

= VO at 25°C after temperature cycle at +25°C to –40°C

O_TC

to +125°C and back to +25°C.

Input Capacitor

Input capacitors are not required on the ADR42x. There is no
limit for the value of the capacitor used on the input, but a 1 µF to
10 µF capacitor on the input will improve transient response in
applications where the supply suddenly changes. An additional

0.1 µF in parallel will also help to reduce noise from the supply.

Output Capacitor

The ADR42x does not need output capacitors for stability
under any load condition. An output capacitor, typically 0.1 µF,
will filter out any low-level noise voltage and will not affect
the operation of the part. On the other hand, the load transient
response can be improved with an additional 1 µF to 10 µF
output capacitor in parallel. A capacitor here will act as a source
of stored energy for sudden increase in load current. The only
parameter that will degrade, by adding an output capacitor, is
turn-on time and it depends on the size of the capacitor chosen.

REV. B

–5–