ANALOG DEVICES AD524 Service Manual

Precision

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FEATURES

Low noise: 0.3 μV p-p at 0.1 Hz to 10 Hz
Low nonlinearity: 0.003% (G = 1)
High CMRR: 120 dB (G = 1000)
Low offset voltage: 50 μV
Low offset voltage drift: 0.5 μV/°C
Gain bandwidth product: 25 MHz
Pin programmable gains of 1, 10, 100, 1000
Input protection, power-on/power-off
No external components required
Internally compensated
MIL-STD-883B and chips available
16-lead ceramic DIP and SOIC packages and 20-terminal

leadless chip carrier available

Available in tape and reel in accordance with EIA-481A

standard

Standard military drawing also available

GENERAL DESCRIPTION

The AD524 is a precision monolithic instrumentation amplifier
designed for data acquisition applications requiring high accu­racy under worst-case operating conditions. An outstanding
combination of high linearity, high common-mode rejection,
low offset voltage drift, and low noise makes the AD524 suitable
for use in many data acquisition systems.

The AD524 has an output offset voltage drift of less than
25 μV/°C, input offset voltage drift of less than 0.5 μV/°C, CMR
above 90 dB at unity gain (120 dB at G = 1000), and maximum
nonlinearity of 0.003% at G = 1. In addition to the outstanding
dc specifications, the AD524 also has a 25 kHz bandwidth
(G = 1000). To make it suitable for high speed data acquisition
systems, the AD524 has an output slew rate of 5 V/μs and settles
in 15 μs to 0.01% for gains of 1 to 100.

As a complete amplifier, the AD524 does not require any exter­nal components for fixed gains of 1, 10, 100 and 1000. For other
gain settings between 1 and 1000, only a single resistor is required.
The AD524 input is fully protected for both power-on and
power-off fault conditions.

The AD524 IC instrumentation amplifier is available in four
different versions of accuracy and operating temperature range.
The economical A grade, the low drift B grade, and lower drift,

Instrumentation Amplifier

AD524

FUNCTIONAL BLOCK DIAGRAM

PROTECTION

1

– INPUT

G = 10

G = 100

G = 1000

RG

RG

+ INPUT

1

2

12

11

16

3

2

PROTECTION

404Ω

40Ω

V

b

20kΩ

20kΩ

Figure 1.

4.44kΩ

13

higher linearity C grade are specified from −25°C to +85°C.
The S grade guarantees performance to specification over the
extended temperature range −55°C to +125°C. The AD524 is
available in a 16-lead ceramic DIP, 16-lead SBDIP, 16-lead SOIC
wide packages, and 20-terminal leadless chip carrier.

PRODUCT HIGHLIGHTS

1. The AD524 has guaranteed low offset voltage, offset

voltage drift, and low noise for precision high gain
applications.

2. The AD524 is functionally complete with pin program-

mable gains of 1, 10, 100, and 1000, and single resistor
programmable for any gain.

3. Input and output offset nulling terminals are provided for

very high precision applications and to minimize offset
voltage changes in gain ranging applications.

4. The AD524 is input protected for both power-on and

power-off fault conditions.

5. The AD524 offers superior dynamic performance with a

gain bandwidth product of 25 MHz, full power response of
75 kHz and a settling time of 15 μs to 0.01% of a 20 V step
(G = 100).

20kΩ

20kΩ

AD524

20kΩ

20kΩ

SENSE

OUTPUT

REFERENCE

00500-001

Rev. F

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
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] www.analog.com
Fax: [phone] ©2007 Analog Devices, Inc. All rights reserved.

AD524

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TABLE OF CONTENTS

Features .............................................................................................. 1

Functional Block Diagram .............................................................. 1

General Description ......................................................................... 1

Product Highlights ........................................................................... 1

Revision History ............................................................................... 2

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

Absolute Maximum Ratings ............................................................ 8

Connection Diagrams .................................................................. 8

ESD Caution .................................................................................. 8

Typical Performance Characteristics ............................................. 9

Test Circuits ................................................................................. 14

Theory of Operation ...................................................................... 15

Input Protection .......................................................................... 15

REVISION HISTORY

11/07—Rev. E to Rev. F

Updated Format .................................................................. Universal

Changes to General Description .................................................... 1

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

Changes to Figure 3 and Figure 4 Captions .................................. 8

Changes to Error Budget Analysis Section ................................. 21

Changes to Ordering Guide .......................................................... 25

4/99—Rev. D to Rev. E

Input Offset and Output Offset ................................................ 15

Gain .............................................................................................. 16

Input Bias Currents .................................................................... 17

Common-Mode Rejection ........................................................ 17

Grounding ................................................................................... 18

Sense Terminal ............................................................................ 18

Reference Terminal .................................................................... 18

Programmable Gain ................................................................... 20

Autozero Circuits ....................................................................... 20

Error Budget Analysis ................................................................ 21

Outline Dimensions ....................................................................... 24

Ordering Guide .......................................................................... 25

Rev. F | Page 2 of 28

AD524

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SPECIFICATIONS

@ VS = ±15 V, RL = 2 kΩ and TA = +25°C, unless otherwise noted.
All min and max specifications are guaranteed. Specifications shown in boldface are tested on all production units at the final electrical

test. Results from those tests are used to calculate outgoing quality levels.

Table 1.

AD524A AD524B
Parameter Min Typ Max Min Typ Max Unit

GAIN

Gain Equation (External Resistor Gain Programming)

Gain Range (Pin Programmable) 1 to 1000 1 to 1000
Gain Error

Nonlinearity

Gain vs. Temperature

VOLTAGE OFFSET (May be Nulled)

Input Offset Voltage

Output Offset Voltage 5

Offset Referred to the Input vs. Supply

INPUT CURRENT

Input Bias Current

Input Offset Current

1

G = 1
G = 10
G = 100
G = 1000

G = 1 ±0.01 ±0.005 %
G = 10, G = 100 ±0.01 ±0.005 %
G = 1000 ±0.01 ±0.01 %

G = 1 5 5 ppm/°C
G = 10 15 10 ppm/°C
G = 100 35 25 ppm/°C
G = 1000 100 50 ppm/°C

vs. Temperature 2

vs. Temperature 100

G = 1
G = 10
G = 100
G = 1000

vs. Temperature ±100 ±100 pA/°C

vs. Temperature ±100 ±100 pA/°C

70
85
95
100

⎡
⎢

R

⎣

⎤

000,40

+

G

±

⎥
⎦

%201

±0.05
±0.25
±0.5
±2.0

250

±50

±35

⎡
⎢
⎣

75
95
105
110

⎤

000,40

+

R

⎥

G

⎦

dB
dB
dB
dB

±

±0.03
±0.15
±0.35
±1.0

100

0.75
3
50

±25

±15

%201

%
%
%
%

μV
μV/°C
mV
μV

nA

nA

Rev. F | Page 3 of 28

AD524

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AD524A AD524B
Parameter Min Typ Max Min Typ Max Unit

INPUT

Input Impedance

Differential Resistance 109 109 Ω
Differential Capacitance 10 10 pF
Common-Mode Resistance 109 109 Ω
Common-Mode Capacitance 10 10 pF

Input Voltage Range

Maximum Differential Input Linear (VDL)
Maximum Common-Mode Linear (VCM)

Common-Mode Rejection DC to 60 Hz with 1 kΩ Source Imbalance V

G = 1
G = 10
G = 100
G = 1000

OUTPUT RATING

V

, RL = 2 kΩ ±10 ±10 V

OUT

DYNAMIC RESPONSE

Small Signal – 3 dB

G = 1 1 1 MHz
G = 10 400 400 kHz
G = 100 150 150 kHz

G = 1000 25 25 kHz
Slew Rate 5.0 5.0 V/μs
Settling Time to 0.01%, 20 V Step

G = 1 to 100 15 15 μs

G = 1000 75 75 μs

NOISE

Voltage Noise, 1 kHz

RTI 7 7 nV/√Hz

RTO 90 90 nV√Hz
RTI, 0.1 Hz to 10 Hz

G = 1 15 15 μV p-p

G = 10 2 2 μV p-p

G = 100, 1000 0.3 0.3 μV p-p
Current Noise

0.1 Hz to 10 Hz 60 60 pA p-p

SENSE INPUT

RIN 20 20 kΩ ± 20%
IIN 15 15 μA
Voltage Range ±10 ±10 V
Gain to Output 1 1 %

REFERENCE INPUT

RIN 40 40 kΩ ± 20%
IIN 15 15 μA
Voltage Range ±10 ±10 V
Gain to Output 1 1 %

2

±10 ±10 V

2

70
90
100
110

G

⎛

V12

⎜
⎝

⎞

×−

V

⎟

D

2

⎠

G

75
95
105
115

⎛

V12

⎜
⎝

dB
dB
dB
dB

⎞

×−

V

⎟

D

2

⎠

V

Rev. F | Page 4 of 28

AD524

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AD524A AD524B

Parameter Min Typ Max Min Typ Max Unit

TEMPERATURE RANGE

Specified Performance –25 +85 –25 +85 °C
Storage –65 +150 –65 +150 °C

POWER SUPPLY

Power Supply Range
Quiescent Current 3.5

1

Does not include effects of external resistor, RG.

2

VOL is the maximum differential input voltage at G = 1 for specified nonlinearity.

VDL at the maximum = 10 V/G.
VD = actual differential input voltage.
Example: G = 10, V
V

= 12 V − (10/2 × 0.50 V) = 9.5 V.

CM

= 0.50.

D

±6

@ V

= ±15 V, RL = 2 kΩ and TA = +25°C, unless otherwise noted.

S

All min and max specifications are guaranteed. Specifications shown in boldface are tested on all production units at the final electrical

test. Results from those tests are used to calculate outgoing quality levels.

Table 2.

AD524C AD524S

Parameter Min Typ Max Min Typ Max Unit

GAIN

Gain Equation (External Resistor Gain Programming)

Gain Range (Pin Programmable) 1 to 1000 1 to 1000
Gain Error

Nonlinearity

Gain vs. Temperature

VOLTAGE OFFSET (May be Nulled)

Input Offset Voltage

Output Offset Voltage

Offset Referred to the Input vs. Supply

1

G = 1
G = 10
G = 100
G = 1000

G = 1 ±0.003 ±0.01 %
G = 10, G = 100 ±0.003 ±0.01 %
G = 1000 ±0.01 ±0.01 %

G = 1 5 5 ppm/°C
G = 10 10 10 ppm/°C
G = 100 25 25 ppm/°C
G = 1000 50 50 ppm/°C

vs. Temperature

vs. Temperature

G = 1
G = 10
G = 100
G = 1000

80
100
110
115

±15

⎡

000,40

⎢
⎣

+

R

G

±18 ±6

5.0

⎤

±

⎥

3.5

%201

⎦

±0.02
±0.1
±0.25
±0.5

50

0.5

2.0
25

75
95
105
110

±15

⎡

000,40

⎢

R

G

⎣

dB
dB
dB
dB

±18

5.0

⎤

+

⎥

%201

±

⎦

±0.05
±0.25
±0.5
±2.0

100

2.0

3.0
50

V
mA

%
%
%
%

μV
μV/°C
mV
μV

Rev. F | Page 5 of 28

AD524

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AD524C AD524S
Parameter Min Typ Max Min Typ Max Unit

INPUT CURRENT

Input Bias Current

vs. Temperature ±100 ±100 pA/°C
Input Offset Current

vs. Temperature ±100 ±100 pA/°C

INPUT

Input Impedance

Differential Resistance 109 109 Ω

Differential Capacitance 10 10 pF

Common-Mode Resistance 109 109 Ω

Common-Mode Capacitance 10 10 pF
Input Voltage Range

Maximum Differential Input Linear (VDL)

Maximum Common-Mode Linear (VCM)

2

±10 ±10 V

2

V12

Common-Mode Rejection DC to 60 Hz with 1 kΩ Source Imbalance V

G = 1

G = 10

G = 100

G = 1000

OUTPUT RATING

V

, RL = 2 kΩ ±10 ±10 V

OUT

DYNAMIC RESPONSE

Small Signal – 3 dB

G = 1 1 1 MHz

G = 10 400 400 kHz

G = 100 150 150 kHz

G = 1000 25 25 kHz
Slew Rate 5.0 5.0 V/μs
Settling Time to 0.01%, 20 V Step

G = 1 to 100 15 15 μs

G = 1000 75 75 μs

NOISE

Voltage Noise, 1 kHz

RTI 7 7 nV/√Hz

RTO 90 90 nV√Hz
RTI, 0.1 Hz to 10 Hz

G = 1 15 15 μV p-p

G = 10 2 2 μV p-p

G = 100, 1000 0.3 0.3 μV p-p
Current Noise

0.1 Hz to 10 Hz 60 60 pA p-p

SENSE INPUT

RIN 20 20 kΩ ± 20%
IIN 15 15 μA
Voltage Range ±10 ±10 V
Gain to Output 1 1 %

80
100
110
120

±15

±10

G

⎛
⎜

⎝

⎞

V

×−

⎟

D

2

⎠

70
90
100
110

±50

±35

G

⎛

V12

⎜
⎝

dB
dB
dB
dB

⎞

V

×−

⎟

D

2

⎠

nA

nA

V

Rev. F | Page 6 of 28

AD524

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AD524C AD524S

Parameter Min Typ Max Min Typ Max Unit

REFERENCE INPUT

RIN 40 40 kΩ ± 20%
IIN 15 15 μA
Voltage Range 10 10 V
Gain to Output 1 1 %

TEMPERATURE RANGE

Specified Performance –25 +85 –55 +85 °C
Storage –65 +150 –65 +150 °C

POWER SUPPLY

Power Supply Range
Quiescent Current 3.5

1

Does not include effects of external resistor RG.

2

VOL is the maximum differential input voltage at G = 1 for specified nonlinearity.

V

at the maximum = 10 V/G.

DL

VD = actual differential input voltage.
Example: G = 10, VD = 0.50.
VCM = 12 V − (10/2 × 0.50 V) = 9.5 V.

±6

±15

±18 ±6

5.0

3.5

±15

±18

5.0

V
mA

Rev. F | Page 7 of 28

AD524

O

O

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ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Supply Voltage ±18 V
Internal Power Dissipation 450 mW
Input Voltage1

(Either Input Simultaneously) |VIN| + |VS| <36 V

Output Short-Circuit Duration Indefinite
Storage Temperature Range

(R) –65°C to +125°C
(D, E) –65°C to +150°C

Operating Temperature Range

AD524A/AD524B/AD524C –25°C to +85°C
AD524S –55°C to +125°C

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

1

Maximum input voltage specification refers to maximum voltage to which

either input terminal may be raised with or without device power applied.
For example, with ±18 volt supplies maximum, VIN is ±18 V; with zero supply
voltage maximum, VIN is ±36 V.

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.

OUTPUT

UTPUT

NULL

RG116

–INPUT

+INPUT

RG

G = 10

NULL

15

1

2

2

3

13

14

4

INPUT

NULL

PAD NUMBERS CORRESPOND TO PIN NUMBERS FOR
THE D-16 AND RW-16 16-L EAD CERAMIC PACKAGES.

G = 100

12

5
INPUT
NULL

G = 1000
11

0.170 (4.33)

SENSE

10

REFERENCE

Figure 2. Metallization Photograph

Contact factory for latest dimensions;

Dimensions shown in inches and (mm)

9
OUTPUT

8 +V

S

0.103
(2.61)

7 –V

S

6

00500-002

NC = NO CONNECT

ESD CAUTION

CONNECTION DIAGRAMS

1

– INPUT

2

+ INPUT

RG

3

2

AD524

INPUT NULL

INPUT NULL

REFERENCE

OFFSET NULL

INPUT NULL

INPUT NULL

REFERENCE

OFFSET NULL

4

TOP VIEW

5

(Not to Scale)

6

–V

7

S

+V

8

S

+V

INPUT

415

S

514

Figure 3. Ceramic (D) and

SOIC (RW-16 and D-16) Packages

1

RG

–INPUT3+INPUT

20

1NC2

4

RG

2

5

AD524

6

NC

7

8

+V

INPUT

S

TOP VIEW

(Not to Scal e)

11NC10

9

S

S

–V

+V

719

518

12

OUTPUT

Figure 4. Leadless Chip Carrier (E)

16

RG

1

15

OUTPUT NULL

14

OUTPUT NULL

13

G = 10

12

G = 100

11

G = 1000

10

SENSE

9

OUTPUT

–V

S

OUTPUT
OFFSET NULL

OUTPUT

NULL

19

18

OUTPUT NULL

17

G = 10

16

NC

15

G = 100

14

G = 1000

13

SENSE

–V

S

OUTPUT
OFFSET NULL

SHORT TO
RG

FOR

2

DESIRED
GAIN

SHORT T
RG2 FOR
DESIRED
GAIN

0500-003

00500-004

Rev. F | Page 8 of 28

AD524

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TYPICAL PERFORMANCE CHARACTERISTICS

20

15

10

+25°C

INPUT VOLTAGE (±V)

5

0

0 5 10 15 20

SUPPLY VOLTAGE (±V)

Figure 5. Input Voltage Range vs. Supply Voltage, G = 1

20

15

10

8

6

4

2

QUIESCE NT CURRENT (mA)

00500-005

0

0 5 10 15 20

SUPPLY VOLTAGE (±V)

00500-008

Figure 8. Quiescent Current vs. Supply Voltage

16

14

12

10

8

5

OUTPUT VOLTAGE SWING (±V)

0

0 5 10 15 20

SUPPLY VOLTAGE (±V)

Figure 6. Output Voltage Swing vs. Supply Voltage

30

20

10

OUTPUT VOLTAGE SWING (V p-p)

0

10 100 1k 10k

LOAD RESI STANCE (Ω)

Figure 7. Output Voltage Swing vs. Load Resistance

6

4

INPUT BI AS CURRENT (±n A)

2

00500-006

0

0 5 10 15 20

SUPPLY VOLTAG E (±V)

00500-009

Figure 9. Input Bias Current vs. Supply Voltage

40

30

20

10

0

–10

–20

INPUT BIAS CURRENT (n A)

–30

00500-007

–40

–75 –25 25 75 125

TEMPERATURE (°C)

00500-010

Figure 10. Input Bias Current vs. Temperature

Rev. F | Page 9 of 28