ANALOG DEVICES AD 8672 ARZ Datasheet

Precision, Very Low Noise, Low Input

–

+

Data Sheet

FEATURES

Very low noise: 2.8 nV/√Hz, 77 nV p-p
Wide bandwidth: 10 MHz
Low input bias current: 12 nA max
Low offset voltage: 75 μV max
High open-loop gain: 120 dB min
Low supply current: 3 mA typ per amplifier
Dual-supply operation: ±5 V to ±15 V
Unity-gain stable
No phase reversal

APPLICATIONS

PLL filters
Filters for GPS
Instrumentation
Sensors and controls
Professional quality audio

GENERAL DESCRIPTION

The AD8671/AD8672/AD8674 are very high precision amplifiers
featuring very low noise, very low offset voltage and drift, low
input bias current, 10 MHz bandwidth, and low power
consumption. Outputs are stable with capacitive loads of over
1000 pF. Supply current is less than 3 mA per amplifier at 30 V.

The AD8671/AD8672/AD8674’s combination of ultralow noise,
high precision, speed, and stability is unmatched. The MSOP
version of the AD8671/AD8672 requires only half the board
space of comparable amplifiers.

Applications for these amplifiers include high quality PLL
filters, precision filters, medical and analytical instrumentation,
precision power supply controls, ATE, data acquisition, and
precision controls as well as professional quality audio.

The AD8671/AD8672 are specified over the extended industrial
temperature range (−40°C to +125°C), and the AD8674 is specified
over the industrial temperature range (−40°C to +85°C).

Bias Current Operational Amplifiers

AD8671/AD8672/AD8674

PIN CONFIGURATIONS

NC

1

AD8671

2

IN

TOP VIEW

IN

3

(Not to Scale)

V–

4

NC = NO CONNECT

Figure 1. 8-Lead SOIC_N (R-8) and 8-Lead MSOP (RM-8)

OUT A

1

AD8672

2

–IN A
+IN A

V–

TOP VIEW

3

(Not to Scale)

4

Figure 2. 8-Lead SOIC-N (R-8) and 8-Lead MSOP (RM-8)

OUT A

1

–IN A

2
3

+IN A

+IN B
–IN B

OUT B

V+

AD8674

4

TOP VIEW

(Not to Scale)

5
6
7

Figure 3. 14-Lead SOIC_N (R-14) and 14-Lead TSSOP (RU-14)

The AD8671, AD8672, and AD8674 are members of a growing
series of low noise op amps offered by Analog Devices, Inc.

Table 1. Voltage Noise

Package 0.9 nV 1.1 nV 1.8 nV 2.8 nV 3.8 nV

Single AD797 AD8597 ADA4004-1 AD8675 AD8671
Dual AD8599 ADA4004-2 AD8676 AD8672
Quad ADA4004-4 AD8674

NC

8
7

V+
OUT

6

NC

5

03718-B-001

V+

8
7

OUT B

6

–IN B
+IN B

5

03718-B-003

OUT D

14

–IN D

13
12

+IN D

11

V–

10

+IN C

9

–IN C
OUT C

8

03718-B-005

The AD8671/AD8672 are available in the 8-lead SOIC and
8-lead MSOP packages. The AD8674 is available in 14-lead
SOIC and 14-lead TSSOP packages.

Surface-mount devices in MSOP packages are available in tape
and reel only.

Rev. F Document Feedback

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devi ces for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] ©2004–2013 Analog Devices, Inc. All rights reserved.

Technical Support www.analog.com

AD8671/AD8672/AD8674 Data Sheet

TABLE OF CONTENTS

Specifications ..................................................................................... 3

Output Phase Reversal ............................................................... 12

Electrical Characteristics, ±5.0 V ............................................... 3

Electrical Characteristics, ±15 V ................................................ 4

Absolute Maximum Ratings ............................................................ 5

ESD Caution .................................................................................. 5

Typical Performance Characteristics ............................................. 6

Applications ..................................................................................... 11

Power Dissipation Calculations ................................................ 11

Unity-Gain Follower Applications ........................................... 11

REVISION HISTORY

3/13—Rev. E to Rev. F

Added Figure 7 .............................................................................. 6

Updated Outline Dimensions ................................................... 15

Changes to Ordering Guide ...................................................... 17

6/10—Rev. D to Rev. E

Added Table 1 and Preceding Sentence ..................................... 1

12/09—Rev. C to Rev. D

Changes to Features and General Description Sections .......... 1

Changes to Absolute Maximum Ratings Section, Table 3,

and Table 4 ................................................................................ 5

Added Power Dissipation Calculations Section ..................... 11

Updated Outline Dimensions ................................................... 15

Changes to Ordering Guide ...................................................... 17

Total Noise vs. Source Resistance ............................................. 12

Total Harmonic Distortion (THD) and Noise ....................... 13

Driving Capacitive Loads .......................................................... 13

GPS Receiver ............................................................................... 14

Band-Pass Filter .......................................................................... 14

PLL Synthesizers and Loop Filters ........................................... 14

Outline Dimensions ....................................................................... 15

Ordering Guide .......................................................................... 17

4/04—Rev. A to Rev. B

Changes to Figure 32 .................................................................. 11

Changes to Figures 36, 37, and 38 ............................................ 12

1/04—Rev. 0 to Rev. A

Added AD8672 and AD8674 parts .............................. Universal

Changes to Specifications ............................................................. 3

Deleted Figure 3 ............................................................................. 6

Changes to Figures 7, 8, and 9 ..................................................... 6

Changes to Figure 37 .................................................................. 12

Added new Figure 32 ................................................................. 10

6/05—Rev. B to Rev. C

Changes to Figure 6 ...................................................................... 1

Updated Outline Dimensions ................................................... 14

Changes to Ordering Guide ...................................................... 16

Rev. F | Page 2 of 20

Data Sheet AD8671/AD8672/AD8674

Offset Voltage Drift

∆VOS/∆T

–40°C < TA < +125°C

–40°C < TA < +125°C

–40

+8

+40

nA

Output Voltage High

VOH

RL = 600 Ω

+3.7

+3.9 V

Settling Time

tS

To 0.1% (4 V step, G = 1)

1.4 µs

f = 10 kHz

–105

dB

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS, ±5.0 V

VS = ±5.0 V, VCM = 0 V, TA = 25°C, unless otherwise noted.

Table 2.

Parameter Symbol Conditions Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage VOS 20 75 µV
–40°C < TA < +125°C 30 125 µV

AD8671 0.3 0.5 µV/°C

AD8672/AD8674 0.3 0.8 µV/°C
Input Bias Current IB –12 +3 +12 nA
+25°C < TA < +125°C –20 +5 +20 nA

Input Offset Current IOS –12 +6 +12 nA
+25°C < TA < +125°C –20 +6 +20 nA
–40°C < TA < +125°C –40 +8 +40 nA
Input Voltage Range –2.5 +2.5 V
Common-Mode Rejection Ratio CMRR VCM = –2.5 V to +2.5 V 100 120 dB
Large Signal Voltage Gain AVO RL = 2 kΩ, VO = –3 V to +3 V 1000 6000 V/mV
Input Capacitance, Common Mode C
Input Capacitance, Differential Mode C
Input Resistance, Common Mode RIN 3.5 GΩ
Input Resistance, Differential Mode R

OUTPUT CHARACTERISTICS

Output Voltage High VOH RL = 2 kΩ, –40°C to +125°C +3.8 +4.0 V
Output Voltage Low VOL RL = 2 kΩ, –40°C to +125°C –3.9 –3.8 V

6.25 pF

INCM

7.5 pF

INDM

15 MΩ

INDM

Output Voltage Low VOL RL = 600 Ω –3.8 –3.7 V
Output Current I

POWER SUPPLY

Power Supply Rejection Ratio PSRR VS = ±4 V to ±18 V

AD8671/AD8672 110 130 dB

AD8674 106 115 dB
Supply Current/Amplifier ISY VO = 0 V 3 3.5 mA

–40°C < TA < +125°C 4.2 mA
DYNAMIC PERFORMANCE

Slew Rate SR RL = 2 kΩ 4 V/µs

To 0.01% (4 V step, G = 1) 5.1 µs
Gain Bandwidth Product GBP 10 MHz

NOISE PERFORMANCE

Peak-to-Peak Noise e
Voltage Noise Density en f = 1 kHz 2.8 3.8 nV/√Hz
Current Noise Density in f = 1 kHz 0.3 pA/√Hz
Channel Separation

AD8672/AD8674 CS f = 1 kHz –130 dB

±10 mA

OUT

0.1 Hz to 10 Hz 77 100 nV p-p

n p-p

Rev. F | Page 3 of 20

AD8671/AD8672/AD8674 Data Sheet

AD8671

0.3

0.5

µV/°C

AD8672/AD8674

0.3

0.8

µV/°C

Input Capacitance, Differential Mode

C

7.5 pF

OUTPUT CHARACTERISTICS

Power Supply Rejection Ratio

PSRR

VS = ±4 V to ±18 V

f = 10 kHz

–105

dB

ELECTRICAL CHARACTERISTICS, ±15 V

VS = ±15 V, VCM = 0 V, TA = 25°C, unless otherwise noted.

Table 3.

Parameter Symbol Conditions Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage VOS 20 75 µV
–40°C < TA < +125°C 30 125 µV
Offset Voltage Drift ∆VOS/∆T –40°C < TA < +125°C

Input Bias Current IB –12 +3 +12 nA
+25°C < TA < +125°C –20 +5 +20 nA
–40°C < TA < +125°C –40 +8 +40 nA
Input Offset Current IOS –12 +6 +12 nA
+25°C < TA < +125°C –20 +6 +20 nA
–40°C < TA < +125°C –40 +8 +40 nA
Input Voltage Range –12 +12 V
Common-Mode Rejection Ratio CMRR VCM = –12 V to +12 V 100 120 dB
Large Signal Voltage Gain AVO RL = 2 kΩ, VO = –10 V to +10 V 1000 6000 V/mV
Input Capacitance, Common Mode C

Input Resistance, Common Mode RIN 3.5 GΩ
Input Resistance, Differential Mode R

6.25 pF

INCM

INDM

15 MΩ

INDM

Output Voltage High VOH RL = 2 kΩ, –40°C to +125°C +13.2 +13.8 V
Output Voltage Low VOL RL = 2 kΩ, –40°C to +125°C –13.8 –13.2 V
Output Voltage High VOH RL = 600 Ω +11 +12.3 V
Output Voltage Low VOL RL = 600 Ω –12.4 –11 V
Output Current I

±20 mA

OUT

Short Circuit Current ISC ±30 mA

POWER SUPPLY

AD8671/AD8672 110 130 dB
AD8674 106 115 dB

Supply Current/Amplifier ISY VO = 0 V 3 3.5 mA
–40°C <TA < +125°C 4.2 mA
DYNAMIC PERFORMANCE

Slew Rate SR RL = 2 kΩ 4 V/µs

Settling Time tS To 0.1% (10 V step, G = 1) 2.2 µs

To 0.01% (10 V step, G = 1) 6.3 µs

Gain Bandwidth Product GBP 10 MHz
NOISE PERFORMANCE

Peak-to-Peak Noise e

0.1 Hz to 10 Hz 77 100 nV p-p

n p-p

Voltage Noise Density en f = 1 kHz 2.8 3.8 nV/√Hz

Current Noise Density in f = 1 kHz 0.3 pA/√Hz

Channel Separation

AD8672/AD8674 CS f = 1 kHz –130 dB

Rev. F | Page 4 of 20

Data Sheet AD8671/AD8672/AD8674

Input Voltage

VS– to VS+

Operating Temperature Range

Package Type

θ

θJC

Unit

the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy

ESD precautions are recommended to avoid performance

ABSOLUTE MAXIMUM RATINGS

Table 4.1

Parameter Rating

Supply Voltage 36 V

Differential Input Voltage ±0.7 V
Output Short-Circuit Duration Indefinite
Storage Temperature Range

All Packages –65°C to +150°C

8-Lead Packages –40°C to +125°C
14-Lead Packages –40°C to +85°C

Junction Temperature Range

All Packages –65°C to +150°C

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

1

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

Stresses above those listed under Absolute Maximum Ratings
may cause permanent 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
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

See the Applications section for a related discussion on power.

Table 5. Package Characteristics

1

JA

8-Lead MSOP (RM) 142 44 °C/W
8-Lead SOIC_N (R) 120 43 °C/W
14-Lead SOIC_N (R) 90 36 °C/W
14-Lead TSSOP (RU) 112 35 °C/W

1

θJA is specified for the worst-case conditions, that is., θJA is specified for the

device soldered on a 4-layer circuit board for surface-mount packages.

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on

electrostatic discharges. Therefore, proper
degradation or loss of functionality.

Rev. F | Page 5 of 20

AD8671/AD8672/AD8674 Data Sheet

03718-B-007

FREQUENCY (Hz)

VOLTAGE NOISE DENSITY (nV/√Hz)

4

8

12

16

20

24

28

32

0

0 10 20 30 40

50

60 70

80 90

100

V

S

=

±

15V

03718-B-008

FREQUENCY (kHz)

VOLTAGE NOISE DENSITY (nV/√Hz)

0

4.5

9.0

13.5

18.0

22.5

27.0

31.5

0 0.1

0.2 0.3 0.4

0.5

0.6

0.7 0.8

0.9

1.0

V

S

=

±

15V

03718-B-009

FREQUENCY (kHz)

VOLTAGE NOISE DENSITY (nV/√Hz)

0

1 102 3 4 5 6 7 8 90

2.5

5.0

7.5

10.0

12.5

15.0

17.5
VS = ±15V

0.1

1

10

1 10

100

1k 10k

CURRENT NOIS E DE NS ITY (pA/√Hz)

FREQUENCY (Hz)

03718-112

0

5

10

15

20

25

30

35

40

45

–35

VOS(µV)

NUMBER OF AMP LIFIE RS

–25 –5–15

0 45–30 –20 –

10 5 10

15 20 25

30 35 40

03718-B-010

V

S

=

±5V

TA = 25

°C

0

5

10

15

20

25

30

35

–35

VOS(µV)

NUMBER OF AMP LIFIE RS

–25 –5–15 0 50–30 –20 –10

5 10 15 20 25 30 35 40

03718-B-011

45

VS = ±

15V

TA = 25°

C

TYPICAL PERFORMANCE CHARACTERISTICS

Figure 4. Voltage Noise Density vs. Frequency

Figure 5. Voltage Noise Density vs. Frequency

Figure 7. Current Noise Density V

= ±15 V

S

Figure 8. Input Offset Voltage Distribution

Figure 6. Voltage Noise Density vs. Frequency

Rev. F | Page 6 of 20

Figure 9. Input Offset Voltage Distribution