ANALOG DEVICES AD524 Service Manual

Precision

Instrumentation Amplifier

AD524

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

FUNCTIONAL BLOCK DIAGRAM

	– INPUT	1	PROTECTION
	G = 10	13	4.44kΩ	AD524
	G = 100	12	404Ω
			Vb	20kΩ
	G = 1000	11	40Ω	SENSE
	RG1	16	20kΩ	20kΩ
				OUTPUT
	RG2	3
			20kΩ	20kΩ
				20kΩ
				REFERENCE
	+ INPUT	2	PROTECTION	-001
				00500

Figure 1.

GENERAL DESCRIPTION

	The AD524 is a precision monolithic instrumentation amplifier	higher linearity C grade are pecified from −25°C to +85°C.
	designed for data acquisition applications requiring high accu-	The S grade guarantees performance to specification over the
	racy under worst-case operating conditions. An outstanding	extended temperature range −55°C to +125°C. The AD524 is
		vailable in 16-lead ceramic DIP, 16-lead SBDIP, 16-lead SOIC
	combination of high linearity, high common-modeMacshbMrejection,
		wide packages, and 20-terminal leadless chip carrier.
	low offset voltage drift, and low noise makes the AD524 suitable
	for use in many data acquisition systems.	PRODUCT HIGHLIGHTS
	The AD524 has an output offset voltage drift of less than	1.	The AD524 has guaranteed low offset voltage, offset
	25 μV/°C, input offset voltage drift of less than 0.5 μV/°C, CMR
			voltage drift, and low noise for precision high gain
	above 90 dB at unity gain (120 dB at G = 1000), and maximum
			applications.
	nonlinearity of 0.003% at G = 1. In addition to the outstanding
		2.	The AD524 is functionally complete with pin program-
	dc specifications, the AD524 also has a 25 kHz bandwidth
			mable gains of 1, 10, 100, and 1000, and single resistor
	(G = 1000). To make it suitable for high speed data acquisition
			programmable for any gain.
	systems, the AD524 has an output slew rate of 5 V/μs and settles
		3. Input and output offset nulling terminals are provided for
	in 15 μs to 0.01% for gains of 1 to 100.
	As a complete amplifier, the AD524 does not require any exter-		very high precision applications and to minimize offset
			voltage changes in gain ranging applications.
	nal components for fixed gains of 1, 10, 100 and 1000. For other
		4.	The AD524 is input protected for both power-on and
	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.
			power-off fault conditions.
		5.	The AD524 offers superior dynamic performance with a
	The AD524 IC instrumentation amplifier is available in four		gain bandwidth product of 25 MHz, full power response of
	different versions of accuracy and operating temperature range.		75 kHz and a settling time of 15 μs to 0.01% of a 20 V step
	The economical A grade, the low drift B grade, and lower drift,		(G = 100).

Rev. F

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibilityisassumedbyAnalogDevicesforitsuse,norforanyinfringementsofpatentsorother rightsofthirdpartiesthatmayresultfromitsuse.Specificationssubjecttochangewithoutnotice.No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.

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Tel: [phone]	www.analog.com
Fax: [phone]	©2007 Analog Devices, Inc. All rights reserved.

AD524

TABLE OF CONTENTS

Features ..............................................................................................	1	Input Offset and Output Offset................................................	15
Functional Block Diagram ..............................................................	1	Gain..............................................................................................	16
General Description .........................................................................	1	Input Bias Currents ....................................................................	17
Product Highlights ...........................................................................	1	Common-Mode Rejection ........................................................	17
Revision History ...............................................................................	2	Grounding ...................................................................................	18
Specifications.....................................................................................	3	Sense Terminal............................................................................	18
Absolute Maximum Ratings............................................................	8	Reference Terminal ....................................................................	18
Connection Diagrams..................................................................	8	Programmable Gain...................................................................	20
ESD Caution..................................................................................	8	Autozero Circuits .......................................................................	20
Typical Performance Characteristics .............................................	9	Error Budget Analysis................................................................	21
Test Circuits.................................................................................	14	Outline Dimensions .......................................................................	24
Theory of Operation ......................................................................	15	Ordering Guide ..........................................................................	25
Input Protection..........................................................................	15

REVISION HISTORY

11/07—Rev. E to Rev. F
Updated Format..................................................................	Universal
Changes to General Description ....................................................	1

Changes to Ordering Guide MacshbM
Changes to Figure 1..........................................................................	1
Changes to Figure 3 and Figure 4 Captions ..................................	8
Changes to Error Budget Analysis Section .................................	21
..........................................................	25

4/99—Rev. D to Rev. E

Rev. F | Page 2 of 28

AD524

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)		40,000				40,000
			+1	±20%				+1	±20%
		RG				RG
Gain Range (Pin Programmable)		1 to 1000				1 to 1000
Gain Error1
G = 1				±0.05					±0.03	%
G = 10				±0.25					±0.15	%
G = 100				±0.5					±0.35	%
G = 1000				±2.0					±1.0	%
Nonlinearity
G = 1				±0.01					±0.005	%
G = 10, G = 100				±0.01					±0.005	%
G = 1000				±0.01					±0.01	%
Gain vs. Temperature	MacshbM100 50									ppm/°C
G = 1000
G = 1				5					5	ppm/°C
G = 10				15					10	ppm/°C
G = 100				35					25	ppm/°C
VOLTAGE OFFSET (May be Nulled)
Input Offset Voltage				250					100	μV
vs. Temperature				2					0.75	μV/°C
Output Offset Voltage				5					3	mV
vs. Temperature				100					50	μV
Offset Referred to the Input vs. Supply
G = 1	70				75					dB
G = 10	85				95					dB
G = 100	95				105					dB
G = 1000	100				110					dB
INPUT CURRENT
Input Bias Current				±50					±25	nA
vs. Temperature		±100				±100				pA/°C
Input Offset Current				±35					±15	nA
vs. Temperature		±100				±100				pA/°C

Rev. F | Page 3 of 28

AD524

			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)2		±10				±10			V
Maximum Common-Mode Linear (VCM)2			G			G			V
		12 V −			× V	12 V −		× V
			2		D	2		D
Common-Mode Rejection DC to 60 Hz with 1 kΩ Source Imbalance									V
G = 1		70				75			dB
G = 10		90				95			dB
G = 100		100				105			dB
G = 1000		110				115			dB
OUTPUT RATING
VOUT, RL = 2 kΩ			±10			±10			V
DYNAMIC RESPONSE
Small Signal – 3 dB
G = 1			1			1			MHz
G = 10			400			400			kHz
G = 100			150			150			kHz
G = 1000		MacshbM							kHz
			25			25
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			%

Rev. F | Page 4 of 28

								AD524
			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		±6	±15	±18	±6	±15	±18	V
Quiescent Current			3.5	5.0		3.5	5.0	mA

1 Does not include effects of external resistor, RG.

2VOL 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, VD = 0.50.

VCM = 12 V − (10/2 × 0.50 V) = 9.5 V.

@ 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 2.

		AD524C					AD524S
Parameter	Min	Typ			Max	Min	Typ		Max	Unit
GAIN
Gain Equation (External Resistor Gain Programming)		40,000					40,000
				+1	±20%			+1	±20%
Gain Error
	MacshbM
		RG					RG
Gain Range (Pin Programmable)		1 to 1000					1 to 1000
1
G = 1					±0.02				±0.05	%
G = 10					±0.1				±0.25	%
G = 100					±0.25				±0.5	%
G = 1000					±0.5				±2.0	%
Nonlinearity
G = 1					±0.003				±0.01	%
G = 10, G = 100					±0.003				±0.01	%
G = 1000					±0.01				±0.01	%
Gain vs. Temperature
G = 1					5				5	ppm/°C
G = 10					10				10	ppm/°C
G = 100					25				25	ppm/°C
G = 1000					50				50	ppm/°C
VOLTAGE OFFSET (May be Nulled)
Input Offset Voltage					50				100	μV
vs. Temperature					0.5				2.0	μV/°C
Output Offset Voltage					2.0				3.0	mV
vs. Temperature					25				50	μV
Offset Referred to the Input vs. Supply
G = 1	80					75				dB
G = 10	100					95				dB
G = 100	110					105				dB
G = 1000	115					110				dB

Rev. F | Page 5 of 28

AD524

		AD524C			AD524S
Parameter		Min Typ		Max	Min Typ		Max	Unit
INPUT CURRENT
Input Bias Current				±15			±50	nA
vs. Temperature		±100			±100			pA/°C
Input Offset Current				±10			±35	nA
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)2		±10			±10			V
Maximum Common-Mode Linear (VCM)2		G			G			V
		12 V −		×V	12 V −		×V
		2		D	2		D
Common-Mode Rejection DC to 60 Hz with 1 kΩ Source Imbalance								V
G = 1		80			70			dB
G = 10		100			90			dB
G = 100		110			100			dB
G = 1000		120			110			dB
OUTPUT RATING
VOUT, RL = 2 kΩ		±10			±10			V
G = 1		MacshbM1 1						MHz
DYNAMIC RESPONSE
Small Signal – 3 dB
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			%

Rev. F | Page 6 of 28

								AD524
			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		±6	±15	±18	±6	±15	±18	V
Quiescent Current			3.5	5.0		3.5	5.0	mA

1 Does not include effects of external resistor RG.

2VOL 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, VD = 0.50.

VCM = 12 V − (10/2 × 0.50 V) = 9.5 V.

MacshbM

Rev. F | Page 7 of 28

AD524

ABSOLUTE MAXIMUM RATINGS

Table 3.

CONNECTION DIAGRAMS

Parameter

Rating

– INPUT

1

16

RG1

+ INPUT

OUTPUT NULL

Supply Voltage

±18 V

2

15

RG2

OUTPUT NULL

Internal Power Dissipation

450 mW

3

14

AD524

Input Voltage1

INPUT NULL

4

13

G = 10

SHORT TO

TOP VIEW

INPUT NULL

G = 100

RG2 FOR

(Either Input Simultaneously) |VIN| + |VS|

<36 V

5

(Not to Scale)

12

DESIRED

Output Short-Circuit Duration

Indefinite

REFERENCE

6

11

G = 1000

GAIN

–VS

Storage Temperature Range

7

10

SENSE

+VS

OUTPUT

(R)

–65°C to +125°C

8

9

(D, E)

–65°C to +150°C

+VS

4

15

–VS

Operating Temperature Range

5

14

-003

AD524A/AD524B/AD524C

–25°C to +85°C

INPUT

OUTPUT

00500

OFFSET NULL

OFFSET NULL

AD524S

–55°C to +125°C

Figure 3. Ceramic (D) and

Lead Temperature (Soldering, 60 sec)

+300°C

SOIC (RW-16 and D-16) Packages

1 Maximum input voltage specification refers to maximum voltage to which

either input terminal may be raised with or without device power applied.

+INPUT

–INPUT

NC

RG

OUTPUT NULL

For example, with ±18 volt supplies maximum, VIN is ±18 V; with zero supply

1

voltage maximum, VIN is ±36 V.

Stresses above those listed under Absolute Maximum Ratings

3

2

1

20

19

may cause permanent damage to the device. This is a stress

RG2 4

18 OUTPUT NULL

rating only; functional operation of the device at these or any

INPUT NULL 5

AD524

17 G = 10

SHORT TO

NC 6

16 NC

other conditions above those indicated in the operational

TOP VIEW

RG2 FOR

INPUT NULL 7

15 G = 100

DESIRED

(Not to Scale)

MacshbM–VS+VSNC

section of this specification is not implied. Exposure to absolute

REFERENCE 8

14 G = 1000

GAIN

maximum rating conditions for extended periods may affect

device reliability.

NC = NO CONNECT

9

10

11

12

13

14

13

12

11

SENSE

OUTPUT

SENSE

OUTPUT

G = 10

G = 100

G = 1000

NULL

10

	OUTPUT
	NULL																	9
	15																	OUTPUT
	RG1 16																	8 +VS
																		0.103
	–INPUT																	(2.61)
	1
	+INPUT
	2																	7 –VS
	RG2
	3
			4					5					6
				INPUT				INPUT						REFERENCE
				NULL				NULL					0.170 (4.33)
																		-002
	PAD NUMBERS CORRESPOND TO PIN NUMBERS FOR
																		00500
	THE D-16 AND RW-16 16-LEAD CERAMIC PACKAGES.

	7	19
+VS			–VS
INPUT	5	18	OUTPUT
OFFSET NULL			OFFSET NULL

Figure 4. Leadless Chip Carrier (E)

ESD CAUTION

00500-004

Figure 2. Metallization Photograph Contact factory for latest dimensions; Dimensions shown in inches and (mm)

Rev. F | Page 8 of 28

TYPICAL PERFORMANCE CHARACTERISTICS

	20
(±V)	15
VOLTAGE	10
INPUT					+25°C
	5							00500-005
	00	5	10		15		20

SUPPLY VOLTAGE (±V)

AD524

CURRENT(mA)	8
	4
	6
QUIESCENT	2
	00				00500-008
		5	10	15	20

SUPPLY VOLTAGE (±V)

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

Figure 8. Quiescent Current vs. Supply Voltage

OUTPUT VOLTAGE SWING (±V)

20								16
							(±nA)	14
15								12
						MacshbMBIASCURRENT 6
								10
10							INPUT	8
5								4
						00500-006		2					00500-009
00	5	10	15		20			00	5	10	15	20
		SUPPLY VOLTAGE (±V)								SUPPLY VOLTAGE (±V)
	Figure 6. Output Voltage Swing vs. Supply Voltage								Figure 9. Input Bias Current vs. Supply Voltage

OUTPUT VOLTAGE SWING (V p-p)

30

20

10

010			00500-007
	100	1k	10k

LOAD RESISTANCE (Ω)

INPUT BIAS CURRENT (nA)

	40
	30
	20
	10
	0
	–10
	–20
	–30				00500-010
	–40
		–25	25	75	125
	–75

TEMPERATURE (°C)

Figure 7. Output Voltage Swing vs. Load Resistance

Figure 10. Input Bias Current vs. Temperature

Rev. F | Page 9 of 28