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AD8571 2 4 a
Datasheet
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Analog Devices AD8571 2 4 a Datasheet

IN AIN A
V
V+ OUT A
NC
1
45
8
AD8571
NC
NC = NO CONNECT
NC
IN A
+IN A
V
OUT B
IN B
+IN B
V+
1
4
5
8
AD8572
OUT A
Input/Output Operational Amplifiers
AD8571/AD8572/AD8574
FEATURES Low Offset Voltage: 1 V Input Offset Drift: 0.005 V/C Rail-to-Rail Input and Output Swing 5 V/2.7 V Single-Supply Operation High Gain, CMRR, PSRR: 130 dB Ultralow Input Bias Current: 20 pA Low Supply Current: 750 A/Op Amp Overload Recovery Time: 50 s No External Capacitors Required
APPLICATIONS Temperature Sensors Pressure Sensors Precision Current Sensing Strain Gage Amplifiers Medical Instrumentation Thermocouple Amplifiers

GENERAL DESCRIPTION

This new family of amplifiers has ultralow offset, drift, and bias current. The AD8571, AD8572, and AD8574 are single, dual, and quad amplifiers, respectively, featuring rail-to-rail input and output swings. All are guaranteed to operate from 2.7 V to 5 V single supply.
The AD857x family provides the benefits previously found only in expensive auto-zeroing or chopper-stabilized amplifiers. Using Analog Devices’ topology, these zero-drift amplifiers combine low cost with high accuracy. (No external capacitors are required.) In addition, using a patented spread-spectrum auto-zero tech­nique, the AD857x family virtually eliminates the intermodulation effects from interaction of the chopping function with the signal frequency in ac applications.
With an offset voltage of only 1 mV and drift of 0.005 mV/∞C, the AD8571 is perfectly suited for applications where error sources cannot be tolerated. Position and pressure sensors, medical equipment, and strain gage amplifiers benefit greatly from nearly zero drift over their operating temperature range. Many more systems require the rail-to-rail input and output swings provided by the AD857x family.
The AD857x family is specified for the extended industrial/ automotive (–40∞C to +125∞C) temperature range. The AD8571 single is available in 8-lead MSOP and narrow 8-lead SOIC packages. The AD8572 dual amplifier is available in 8-lead narrow SOIC and 8-lead TSSOP surface mount packages. The AD8574 quad is available in narrow 14-lead SOIC and 14-lead TSSOP packages.
8-Lead MSOP
(RM Suffix)
8-Lead TSSOP
(RU Suffix)
14-Lead TSSOP
(RU Suffix)
V
1
AD8574
78
OUT A
IN AIN A
N B
IN B
OUT B

PIN CONFIGURATIONS

8-Lead SOIC
(R Suffix)
1
NC
IN A
2
+IN A
3
V
4
NC = NO CONNECT
8-Lead SOIC
(R Suffix)
1
OUT A
IN A
2
3
+IN A
V
4
14-Lead SOIC
(R Suffix)
OUT A
OUT D
14
IN DIN D
V
IN CIN C
OUT C
IN A
+IN A
+IN B
IN B
OUT B
1
2
3
V+
4
5
6
7
AD8571
AD8572
AD8574
8
7
6
5
8
7
6
5
14
13
12
11
10
9
8
NC
V+
OUT A
NC
V+
OUT B
IN B
+IN B
OUT D
IN D
+IN D
V
+IN C
IN C
OUT C
REV. A
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. Trademarks and registered trademarks are the property of their respective companies.
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 © 2003 Analog Devices, Inc. All rights reserved.
AD8571/AD8572/AD8574–SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

(VS = 5 V, VCM = 2.5 V, VO = 2.5 V, TA = 25C, unless otherwise noted.)
Parameter Symbol Conditions Min Typ Max Unit
INPUT CHARACTERISTICS
Offset Voltage V
Input Bias Current I
Input Offset Current I
B
OS
OS
–40∞C £ T
–40∞C £ T
–40∞C £ T
£ +125∞C10mV
A
£ +125∞C 1.0 1.5 nA
A
£ +125∞C 150 200 pA
A
15 mV
10 50 pA
20 70 pA
Input Voltage Range 05V Common-Mode Rejection Ratio CMRR V
Large Signal Voltage Gain* A
VO
= 0 V to 5 V 120 140 dB
CM
–40∞C £ T
£ +125∞C 115 130 dB
A
RL = 10 kW, VO = 0.3 V to 4.7 V 125 145 dB –40∞C £ T
£ +125∞C 120 135 dB
A
Offset Voltage Drift DVOS/DT –40∞C £ TA £ +125∞C 0.005 0.04 mV/∞C
OUTPUT CHARACTERISTICS
Output Voltage High V
OH
RL = 100 kW to GND 4.99 4.998 V –40∞C to +125∞C 4.99 4.997 V
= 10 kW to GND 4.95 4.98 V
R
L
–40∞C to +125∞C 4.95 4.975 V
Output Voltage Low V
OL
RL = 100 kW to V+ 1 10 mV –40∞C to +125∞C210mV
= 10 kW to V+ 10 30 mV
R
L
–40∞C to +125∞C1530mV
Short Circuit Limit I
SC
±25 ±50 mA
–40∞C to +125∞C ±40 mA
Output Current I
O
±30 mA
–40∞C to +125∞C ±15 mA
POWER SUPPLY
Power Supply Rejection Ratio PSRR VS = 2.7 V to 5.5 V 120 130 dB
£ +125∞C 115 130 dB
A
Supply Current/Amplifier I
SY
–40∞C £ T VO = 0 V 850 975 mA –40∞C £ TA £ +125∞C 1,000 1,075 mA
DYNAMIC PERFORMANCE
Slew Rate SR RL = 10 kW 0.4 V/ms Overload Recovery Time 0.05 0.3 ms Gain Bandwidth Product GBP 1.5 MHz
NOISE PERFORMANCE
Voltage Noise e
Voltage Noise Density e Current Noise Density i
*Gain testing is highly dependent upon test bandwidth.
Specifications subject to change without notice.
p-p 0 Hz to 10 Hz 1.3 mV p-p
n
e
p-p 0 Hz to 1 Hz 0.41 mV p-p
n
n
n
f = 1 kHz 51 nV/÷Hz f = 10 Hz 2 fA/÷Hz
REV. A–2–
AD8571/AD8572/AD8574
ELECTRICAL CHARACTERISTICS
(VS = 2.7 V, VCM = 1.35 V, VO = 1.35 V, TA = 25C, unless otherwise noted.)
Parameter Symbol Conditions Min Typ Max Unit
INPUT CHARACTERISTICS
Offset Voltage V
Input Bias Current I
Input Offset Current I
B
OS
OS
–40∞C £ T
–40∞C £ T
–40∞C £ T
£ +125∞C10mV
A
£ +125∞C 1.0 1.5 nA
A
£ +125∞C 150 200 pA
A
15 mV
10 50 pA
10 50 pA
Input Voltage Range 0 2.7 V Common-Mode Rejection Ratio CMRR V
Large Signal Voltage Gain* A
VO
= 0 V to 2.7 V 115 130 dB
CM
–40∞C £ T
£ +125∞C 110 130 dB
A
RL = 10 kW, VO = 0.3 V to 2.4 V 110 140 dB –40∞C £ T
£ +125∞C 105 130 dB
A
Offset Voltage Drift DVOS/DT –40∞C £ TA £ +125∞C 0.005 0.04 mV/∞C
OUTPUT CHARACTERISTICS
Output Voltage High V
OH
RL = 100 kW to GND 2.685 2.697 V –40∞C to +125∞C 2.685 2.696 V
= 10 kW to GND 2.67 2.68 V
R
L
–40∞C to +125∞C2.67 2.675 V
Output Voltage Low V
OL
RL = 100 kW to V+ 1 10 mV –40∞C to +125∞C210mV
= 10 kW to V+ 10 20 mV
R
L
–40∞C to +125∞C1520mV
Short Circuit Limit I
SC
±10 ±15 mA
–40∞C to +125∞C ±10 mA
Output Current I
O
±10 mA
–40∞C to +125∞C ±5mA
POWER SUPPLY
Power Supply Rejection Ratio PSRR VS = 2.7 V to 5.5 V 120 130 dB
£ +125∞C 115 130 dB
A
Supply Current/Amplifier I
SY
–40∞C £ T VO = 0 V 750 900 mA –40∞C £ TA £ +125∞C 950 1,000 mA
DYNAMIC PERFORMANCE
Slew Rate SR RL = 10 kW 0.5 V/ms Overload Recovery Time 0.05 ms Gain Bandwidth Product GBP 1 MHz
NOISE PERFORMANCE
Voltage Noise e Voltage Noise Density e Current Noise Density i
*Gain testing is highly dependent upon test bandwidth.
Specifications subject to change without notice.
p-p 0 Hz to 10 Hz 2.0 mV p-p
n
n
n
f = 1 kHz 94 nV/÷Hz f = 10 Hz 2 fA/÷Hz
REV. A
–3–
AD8571/AD8572/AD8574

ABSOLUTE MAXIMUM RATINGS

1
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 V
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . GND to V
Differential Input Voltage
2
. . . . . . . . . . . . . . . . . . . . . . . ± 5.0 V
+ 0.3 V
S
ESD (Human Body Model) . . . . . . . . . . . . . . . . . . . . . 2,000 V
Output Short-Circuit Duration to GND . . . . . . . . . . Indefinite
Storage Temperature Range
RM, RU, and R Packages . . . . . . . . . . . . . –65∞C to +150∞C
Operating Temperature Range
AD8571A/AD8572A/AD8574A . . . . . . . . . –40∞C to +125∞C
Junction Temperature Range
RM, RU, and R Packages . . . . . . . . . . . . . –65∞C to +150∞C
Lead Temperature Range (Soldering, 60 sec) . . . . . . . . 300∞C
NOTES
1
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 listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
2
Differential input voltage is limited to ± 5.0 V or the supply voltage, whichever is less.

ORDERING GUIDE

Temperature Package Package
Model Range Description Option Branding
AD8571AR –40⬚C to +125⬚C 8-Lead SOIC R-8 AD8571AR-REEL –40⬚C to +125⬚C 8-Lead SOIC R-8 AD8571AR-REEL7 –40⬚C to +125⬚C 8-Lead SOIC R-8 AD8571ARM-R2 –40⬚C to +125⬚C 8-Lead MSOP RM-8 AJA AD8571ARM-REEL –40⬚C to +125⬚C 8-Lead MSOP RM-8 AJA AD8572AR –40⬚C to +125⬚C 8-Lead SOIC R-8 AD8572AR-REEL –40⬚C to +125⬚C 8-Lead SOIC R-8 AD8572AR-REEL7 –40⬚C to +125⬚C 8-Lead SOIC R-8 AD8572ARU –40⬚C to +125⬚C 8-Lead TSSOP RU-8 AD8572ARU-REEL –40⬚C to +125⬚C 8-Lead TSSOP RU-8 AD8574AR –40⬚C to +125⬚C 14-Lead TSSOP R-14 AD8574AR-REEL –40⬚C to +125⬚C 14-Lead SOIC R-14 AD8574AR-REEL7 –40⬚C to +125⬚C 14-Lead SOIC R-14 AD8574ARU –40⬚C to +125⬚C 14-Lead TSSOP RU-14 AD8574ARU-REEL –40⬚C to +125⬚C 14-Lead TSSOP RU-14
Package Type JA*
JC
Unit
8-Lead MSOP (RM) 190 44 ∞C/W 8-Lead TSSOP (RU) 240 43 ∞C/W 8-Lead SOIC (R) 158 43 ∞C/W 14-Lead TSSOP (RU) 180 36 ∞C/W 14-Lead SOIC (R) 120 36 ∞C/W
*␪JA is specified for worst-case conditions, i.e., ␪
socket for P-DIP packages, ␪ for SOIC and TSSOP packages.
is specified for device soldered in circuit board
JA
is specified for device in
JA
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 AD8571/AD8572/AD8574 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.
REV. A–4–
Typical Performance Characteristics–AD8571/AD8572/AD8574
)
)
COMMON-MODE VOLTAGE (V)
INPUT BIAS CURRENT (pA)
1,500
2,000
01
5
234
1,000
500
0
1,000
1,500
500
VS = 5V T
A
= 125C
)
180
160
140
120
100
80
60
NUMBER OF AMPLIFIERS
40
20
0
2.5
1.5 0.5
OFFSET VOLTAGE (V)
0.5
TPC 1. Input Offset Voltage Distribution at 2.7 V
180
160
140
120
100
80
60
NUMBER OF AMPLIFIERS
40
20
0
2.5
1.5 0.5
OFFSET VOLTAGE (V)
0.5 2.5
TPC 4. Input Offset Voltage Distribution at 5 V
VS = 2.7V
= 1.35V
V
CM
= 25C
T
A
1.5
VS = 5V
= 2.5V
V
CM
= 25C
T
A
1.5
2.5
50
VS = 5V
40
= 40C, +25C, +85C
T
A
30
20
10
0
10
INPUT BIAS CURRENT (pA)
20
30
01
INPUT COMMON-MODE VOLTAGE (V)
234
+85C
+25C
40C
TPC 2. Input Bias Current vs. Common-Mode Voltage
12
VS = 5V
= 2.5V
V
10
8
6
4
NUMBER OF AMPLIFIERS
2
0
01 6
INPUT OFFSET DRIFT (nV/C
CM
= 40C TO +125C
T
A
23 4 5
TPC 5. Input Offset Voltage Drift Distribution at 5 V
5
TPC 3. Input Bias Current vs. Common-Mode Voltage
10k
VS = 5V
= 25C
T
A
1k
100
10
OUTPUT VOLTAGE (mV)
1
0.1
0.0001 0.01
0.001
SOURCE
LOAD CURRENT (mA)
0.1
SINK
110
100
TPC 6. Output Voltage to Supply Rail vs. Output Current at 5 V
10k
1k
100
10
OUTPUT VOLTAGE (mV)
1
0.1
0.0001 0.01
TPC 7. Output Voltage to Supply Rail vs. Output Current at 2.7 V
REV. A
VS = 2.7V
= 25C
T
A
SOURCE SINK
0.001
0.1
LOAD CURRENT (mA
110
100
1,000
VCM = 2.5V
= 5V
V
S
750
500
250
INPUT BIAS CURRENT (pA)
0
75 50
25
0255075100
TEMPERATURE (C)
125
150
TPC 8. Bias Current vs. Temperature
–5–
1.0
0.8
0.6
0.4
SUPPLY CURRENT (mA)
0.2
0
75 50
0
25
25 50 75 100
TEMPERATURE (C
TPC 9. Supply Current vs. Temperature
5V
2.7V
150
125
AD8571/AD8572/AD8574
(
g
)
(Hz)
(
g
)
800
TA = 25C
700
600
500
400
300
200
100
SUPPLY CURRENT PER AMPLIFIER (A)
0
0
16
2345
SUPPLY VOLTAGE (V)
TPC 10. Supply Current vs. Supply Voltage
60
50
40
AV = 100
30
20
AV = 10
10
0
AV = +1
10
CLOSED-LOOP GAIN (dB)
20
30
40
100 1k 10M10k 100k 1M
FREQUENCY (Hz)
VS = 2.7V C R
TPC 13. Closed Loop Gain vs. Frequency at 2.7 V
= 0pF
L
= 2k
L
60
VS = 2.7V
50
40
30
20
10
10
OPEN-LOOP GAIN (dB)
20
30
40
= 0pF
C
L
=
R
L
0
10k 100k 100M1M 10M
FREQUENCY (Hz)
0
45
90
135
180
225
270
TPC 11. Open-Loop Gain and Phase Shift vs. Frequency at 2.7 V
60
50
40
AV = 100
30
20
AV = 10
10
0
AV = +1
10
CLOSED-LOOP GAIN (dB)
20
30
40
100 1k 10M10k 100k 1M
FREQUENCY
VS = 5V
= 0pF
C
L
= 2k
R
L
TPC 14. Closed Loop Gain vs. Frequency at 5 V
60
VS = 5V
50
40
30
rees
20
De
10
10
OPEN-LOOP GAIN (dB)
PHASE SHIFT
20
30
40
= 0pF
C
L
=
R
L
0
10k 100k 100M1M 10M
FREQUENCY (Hz)
TPC 12. Open-Loop Gain and Phase Shift vs. Frequency at 5 V
300
VS = 2.7V
270
240
210
180
150
120
90
OUTPUT IMPEDANCE ()
60
30
0
100 1k 10M10k 100k 1M
AV = 100
FREQUENCY (Hz)
TPC 15. Output Impedance vs. Frequency at 2.7 V
AV = 1
AV = 10
0
45
90
135
180
225
270
rees
De
PHASE SHIFT
300
VS = 5V
270
240
210
180
150
120
90
OUTPUT IMPEDANCE ()
60
30
0
100 1k 10M10k 100k 1M
AV = 100
FREQUENCY (Hz)
TPC 16. Output Impedance vs. Frequency at 5 V
AV = 10
AV = 1
VS = 2.7V
= 300pF
C
L
= 2k
R
L
= 1
A
V
2s
500mV
TPC 17. Large Signal Transient Response at 2.7 V
VS = +5V
= 300pF
C
L
R
= 2k
L
= 1
A
V
5s
1V
TPC 18. Large Signal Transient Response at 5 V
REV. A–6–
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