Precision Instrumentation Amplifier
Enhanced Product AD8221-EP
Rev. 0 Document Feedback
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FEATURES
Specified from −55°C to +125°C
0.9 μV/°C maximum input offset average TC
10 ppm/°C maximum gain vs. temperature (G = 1)
Excellent ac specifications
80 dB minimum CMRR at 10 kHz (G = 1)
–3 dB bandwidth: 825 kHz typical (G = 1)
2 V/μs typical slew rate
Low noise
8 nV/√Hz, at 1 kHz, maximum input voltage noise
0.25 μV p-p RTI (G = 100 to 1000)
High accuracy dc performance
80 dB minimum CMRR DC to 60 Hz (G = 1)
70 μV maximum input offset voltage
2 nA maximum input bias current
Wide power supply range: ±2.3 V to ±18 V
Available in space-saving MSOP
Gain set with 1 external resistor (gain range 1 to 1000)
ENHANCED PRODUCT FEATURES
Supports defense and aerospace applications (AQEC standard)
Military temperature range (−55°C to +125°C)
Controlled manufacturing baseline
One assembly/test site
One fabrication site
Enhanced product change notification
Qualification data available on request
APPLICATIONS
Bridge amplifiers
Precision data acquisition systems
Strain gages
Transducer interfaces
TYPICAL CONNECTION DIAGRAM
8
7
6
5
1
2
3
4
–IN
R
G
R
G
+V
S
V
OUT
REF
–V
S
+
IN
TOP VIEW
A
D8221-EP
03149-001
Figure 1.
GENERAL DESCRIPTION
The AD8221-EP is a gain programmable, high performance
instrumentation amplifier that delivers the industry’s highest
CMRR over frequency in its class. The CMRR of instrumentation
amplifiers on the market today falls off at 200 Hz. In contrast, the
AD8221-EP maintains a minimum CMRR of 80 dB to 10 kHz at
G = 1. High CMRR over frequency allows the AD8221-EP to
reject wideband interference and line harmonics, greatly
simplifying filter requirements.
Possible applications include precision data acquisition, biomedical
analysis, and aerospace instrumentation.
Low voltage offset, low offset drift, low gain drift, high gain
accuracy, and high CMRR make this device an excellent choice
in applications that demand the best dc performance possible, such
as bridge signal conditioning.
Programmable gain affords the user design flexibility. A single
resistor sets the gain from 1 to 1000. The AD8221-EP operates
on both single and dual supplies and is well suited for applications
where ±10 V input voltages are encountered.
The AD8221-EP is specified over the −55°C to +125°C military
temperature range. It is available in an 8-lead MSOP package.
Additional application and technical information can be found
in the AD8221 data sheet.
40
50
60
70
80
90
CMRR (dB)
100
110
120
FREQUENCY (Hz)
10010 1k 10k 100k
AD8221-EP
COMPETITOR 1
COMPETITOR 2
13702-002
Figure 2. Typical CMRR vs. Frequency for G = 1
AD8221-EP Enhanced Product
Rev. 0 | Page 2 of 14
TABLE OF CONTENTS
Features .............................................................................................. 1
Enhanced Product Features ............................................................ 1
Applications ....................................................................................... 1
Typical Connection Diagram .......................................................... 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 5
Thermal Characteristics ...............................................................5
ESD Caution...................................................................................5
Pin Configuration and Function Descriptions ..............................6
Typical Performance Characteristics ..............................................7
Outline Dimensions ....................................................................... 14
Ordering Guide .......................................................................... 14
REVISION HISTORY
4/16—Revision 0: Initial Version
Enhanced Product AD8221-EP
Rev. 0 | Page 3 of 14
SPECIFICATIONS
VS = ±15 V, VREF = 0 V, TA = 25°C, G = 1, RL = 2 kΩ, unless otherwise noted.
Table 1.
Parameter Test Conditions/Comments Min Typ Max Unit
COMMON-MODE REJECTION RATIO (CMRR)
CMRR DC to 60 Hz with 1 kΩ Source Imbalance VCM = −10 V to +10 V
G = 1 80 dB
G = 10 100 dB
G = 100 120 dB
G = 1000 130 dB
CMRR at 10 kHz VCM = –10 V to +10 V
G = 1 80 dB
G = 10 90 dB
G = 100 100 dB
G = 1000 100 dB
NOISE RTI noise = √eNI2 + (eNO/G)2
Voltage Noise, 1 kHz
Input Voltage Noise, eNI V
IN+, VIN−, VREF = 0 8 nV/√Hz
Output Voltage Noise, eNO 75 nV/√Hz
Referred to Input (RTI) f = 0.1 Hz to 10 Hz
G = 1 2 μV p-p
G = 10 0.5 μV p-p
G = 100 to 1000 0.25 μV p-p
Current Noise f = 1 kHz 40 fA/√Hz
f = 0.1 Hz to 10 Hz 6 pA p-p
VOLTAGE OFFSET1
Input Offset, VOSI V
S = ±5 V to ±15 V 70 μV
Over Temperature TA = −55°C to +125°C 150 μV
Average Temperature Coefficient (TC) 0.9 μV/°C
Output Offset, VOSO V
S = ±5 V to ±15 V 600 μV
Over Temperature TA = −55°C to +125°C 1.2 mV
Average TC 9 μV/°C
Offset RTI vs. Supply (PSR) VS = ±2.3 V to ±18 V
G = 1 90 100 dB
G = 10 100 120 dB
G = 100 120 140 dB
G = 1000 120 140 dB
INPUT CURRENT
Input Bias Current 0.5 2 nA
Over Temperature TA = −55°C to +125°C 3.75 nA
Average TC 11 pA/°C
Input Offset Current 0.3 1 nA
Over Temperature TA = −55°C to +125°C 2.25 nA
Average TC 7 pA/°C
REFERENCE INPUT
RIN 20 kΩ
IIN V
IN+, VIN−, VREF = 0 50 60 μA
Voltage Range −VS +VS V
Gain to Output 1 ± 0.0001 V/V
AD8221-EP Enhanced Product
Rev. 0 | Page 4 of 14
Parameter Test Conditions/Comments Min Typ Max Unit
POWER SUPPLY
Operating Range VS = ±2.3 V to ±18 V ±2.3 ±18 V
Quiescent Current 0.9 1 mA
Over Temperature TA = −55°C to +125°C 1 1.2 mA
DYNAMIC RESPONSE
Small Signal −3 dB Bandwidth
G = 1 825 kHz
G = 10 562 kHz
G = 100 100 kHz
G = 1000 14.7 kHz
Settling Time 0.01% 10 V step
G = 1 to 100 10 μs
G = 1000 80 μs
Settling Time 0.001% 10 V step
G = 1 to 100 13 μs
G = 1000 110 μs
Slew Rate G = 1 1.5 2 V/μs
G = 5 to 100 2 2.5 V/μs
GAIN G = 1 + (49.4 kΩ/RG)
Gain Range 1 1000 V/V
Gain Error VOUT ± 10 V
G = 1 0.1 %
G = 10 0.3 %
G = 100 0.3 %
G = 1000 0.3 %
Gain Nonlinearity VOUT = −10 V to +10 V
G = 1 to 10 RL = 10 kΩ 5 15 ppm
G = 100 RL = 10 kΩ 7 20 ppm
G = 1000 RL = 10 kΩ 10 50 ppm
G = 1 to 100 RL = 2 kΩ 15 100 ppm
Gain vs. Temperature
G = 1 3 10 ppm/°C
G > 12 –50 ppm/°C
INPUT
Input Impedance
Differential 100||2 GΩ||pF
Common Mode 100||2 GΩ||pF
Input Operating Voltage Range3 V
S = ±2.3 V to ±5 V –VS + 1.9 +VS − 1.1 V
Over Temperature TA = −55°C to +125°C –VS + 2.0 +VS − 1.2 V
Input Operating Voltage Range VS = ±5 V to ±18 V –VS + 1.9 +VS − 1.2 V
Over Temperature TA = −55°C to +125°C –VS + 2.0 +VS − 1.3 V
OUTPUT RL = 10 kΩ
Output Swing VS = ±2.3 V to ±5 V –VS + 1.1 +VS − 1.2 V
Over Temperature TA = −55°C to +125°C –VS + 1.4 +VS − 1.3 V
Output Swing VS = ±5 V to ±18 V –VS + 1.2 +VS − 1.4 V
Over Temperature TA = −55°C to +125°C –VS + 1.6 +VS − 1.5 V
Short-Circuit Current 18 mA
TEMPERATURE RANGE
Specified Performance −55 +125 °C
1 Total RTI VOS = (VOSI) + (VOSO/G).
2 Does not include the effects of external resistor RG.
3 One input grounded. G = 1.
Enhanced Product AD8221-EP
Rev. 0 | Page 5 of 14
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter Rating
Supply Voltage ±18 V
Internal Power Dissipation 200 mW
Output Short-Circuit Current Indefinite
Input Voltage (Common-Mode) ±VS
Differential Input Voltage ±VS
Storage Temperature Range −65°C to +150°C
Operating Temperature Range −55°C to +125°C
Stresses at or above those listed under Absolute Maximum
Ratings may cause permanent damage to the product. This is a
stress rating only; functional operation of the product at these
or any other conditions above those indicated in the operational
section of this specification is not implied. Operation beyond
the maximum operating conditions for extended periods may
affect product reliability.
THERMAL CHARACTERISTICS
Specification for a device in free air.
Table 3.
Package θJA Unit
8-Lead MSOP, 4-Layer JEDEC Board 135 °C/W
ESD CAUTION
AD8221-EP Enhanced Product
Rev. 0 | Page 6 of 14
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
TOP VIEW
(Not to Scale)
–
IN
1
R
G2
R
G3
+IN
4
+V
S
8
V
OUT
7
REF
6
–V
S
5
AD8221-EP
13702-103
Figure 3. Pin Configuration
Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1 −IN Negative Input Terminal.
2, 3 RG Gain Setting Terminal. Place resistor across the RG pins to set the gain. G = 1 + (49.4 kΩ/RG).
4 +IN Positive Input Terminal.
5 −VS Negative Power Supply Terminal.
6 REF Reference Voltage Terminal. Drive this terminal with a low impedance voltage source to level-shift the output.
7 VOUT Output Terminal.
8 +VS Positive Power Supply Terminal.
Enhanced Product AD8221-EP
Rev. 0 | Page 7 of 14
TYPICAL PERFORMANCE CHARACTERISTICS
T = 25°C, VS = ±15 V, RL = 10 kΩ, unless otherwise noted.
0
200
400
600
800
1000
UNITS
1200
1400
1600
0–50–100–150 50 100 150
CMR (µV/V)
13702-003
Figure 4. Typical Distribution for CMR (G = 1)
0
300
600
900
1200
1500
UNITS
1800
2100
2400
0–20–40–60 204060
INPUT OFFSET VOLTAGE (µV)
13702-004
Figure 5. Typical Distribution of Input Offset Voltage
0
500
1000
1500
2000
2500
3000
UNITS
0–0.5–1.0–1.5 0.5 1.0 1.5
INPUT BIAS CURRENT (nA)
13702-005
Figure 6. Typical Distribution of Input Bias Current
0
500
1000
1500
2000
2500
3000
3500
UNITS
0–0.3–0.6–0.9 0.3 0.6 0.9
INPUT OFFSET CURRENT (nA)
13702-006
Figure 7. Typical Distribution of Input Offset Current
–15
–10
–5
0
5
10
15
INPUT COMMON-MODE V
O
LTAGE (V)
–5 0–15 –10 5 10 15
OUTPUT VOLTAGE (V)
V
S
= ±5V
V
S
= ±15V
13702-007
Figure 8. Input Common-Mode Voltage vs. Output Voltage, G = 1
–15
–10
–5
0
5
10
15
INPUT COMMON-MODE V
O
LTAGE (V)
–5 0–15 –10 5 10 15
OUTPUT VOLTAGE (V)
V
S
= ±5V
V
S
= ±15V
13702-008
Figure 9. Input Common-Mode Voltage vs. Output Voltage, G = 100
AD8221-EP Enhanced Product
Rev. 0 | Page 8 of 14
0.40
0.45
0.50
0.55
0.60
0.65
INPUT BIAS CURRENT (nA)
0.70
0.75
0.80
–5 0–15 –10 5 10 15
COMMON-MODE VOLTAGE (V)
VS = ±5V
VS = ±15V
13702-009
Figure 10. Input Bias Current (IBIAS) vs. Common-Mode Voltage (CMV)
0
0.25
0.50
0.75
1.00
1.25
CHANGE IN INPUT OFFSET V
O
LTAGE (µV)
1.50
1.75
2.00
0.10.01 1 10
WARM-UP TIME (min)
13702-010
Figure 11. Change in Input Offset Voltage vs. Warm-Up Time
–55–40–25–10 5 203550658095110125
INPUT CURRENT (nA)
TEMPERATURE (°C)
VS = ±15V
INPUT BIAS CURRENT
INPUT OFFSET CURRENT
13702-011
–5
–4
–3
–2
–1
0
1
2
3
4
5
Figure 12. Input Offset Current and Input Bias Current vs. Temperature
20
40
60
80
100
120
POSITIVE PSRR (dB)
140
160
180
0.1 1 10 100 1k 10k 100k 1M
FREQUENCY (Hz)
GAIN = 1
GAIN = 10
GAIN = 100
GAIN = 1000
GAIN = 1000
13702-012
Figure 13. Positive PSRR vs. Frequency, RTI (G = 1 to 1000)
20
40
60
80
100
120
NE
G
A
TIVE PSRR (dB)
140
160
180
0.1 1 10 100 1k 10k 100k 1M
FREQUENCY (Hz)
GAIN = 1
GAIN = 10
GAIN = 100
GAIN = 1000
13702-013
Figure 14. Negative PSRR vs. Frequency, RTI (G = 1 to 1000)
–30
–20
–10
0
10
20
30
40
50
60
70
100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
GAIN (dB)
GAIN = 1000
GAIN = 100
GAIN = 10
GAIN = 1
13702-015
Figure 15. Gain vs. Frequency
Enhanced Product AD8221-EP
Rev. 0 | Page 9 of 14
40
60
80
100
CMRR (dB)
120
140
160
0.1 1 10 100 1k 10k 100k 1M
FREQUENCY (Hz)
GAIN = 1000
GAIN = 100
GAIN = 10
GAIN = 1
13702-016
Figure 16. CMRR vs. Frequency, RTI
40
60
80
100
CMRR (dB)
120
140
160
0.1 1 10 100 1k 10k 100k 1M
FREQUENCY (Hz)
GAIN = 1000
GAIN = 100
GAIN = 10
GAIN = 1
13702-017
Figure 17. CMRR vs. Frequency, RTI, 1 kΩ Source Imbalance
–100
–80
–60
–40
–20
0
20
40
60
80
100
CMR (µV/V)
TEMPERATURE ( °C)
–55–40–25–10 5 203550658095110125
13702-018
Figure 18. CMR vs. Temperature
–V
S
+0
+0.4
+0.8
+1.2
+1.6
+2.0
+2.4
–1.6
–2.0
–2.4
–1.2
–0.8
–0.4
+V
S
–0
INPUT VOL
T
AGE LIMIT (V)
REFERRED TO SUPPLY VOLTAGES
SUPPLY VOLTAGE ( ±V)
50101520
13702-019
Figure 19. Input Voltage Limit vs. Supply Voltage, G = 1
–V
S
+0
+0.4
+0.8
+1.2
+1.6
+2.0
–1.6
–2.0
–1.2
–0.8
–0.4
+
V
S
–
0
OUTPUT VOL
T
AGE SWING (V)
REFERRED TO SUPPLY VOLTAGES
SUPPLY VOLTAGE (±V)
50 101520
R
L
= 10kΩ
R
L
= 2kΩ
R
L
= 10kΩ
R
L
= 2kΩ
13702-020
Figure 20. Output Voltage Swing vs. Supply Voltage, G = 1
OUTPUT VOLTAGE SWING (V p-p)
0
20
10
30
LOAD RESISTANCE (Ω)
101 100 1k 10k
V
S
= ±15V
13702-021
Figure 21. Output Voltage Swing vs. Load Resistance
AD8221-EP Enhanced Product
Rev. 0 | Page 10 of 14
–V
S
+0
+1
+2
+3
–3
–2
–1
+
V
S
–0
OUTPUT VOLTAGE SWING (V)
REFERRED TO SUPPLY VOLTAGES
0123456789101112
OUTPUT CURRENT (mA)
SOURCING
SINKING
13702-022
Figure 22. Output Voltage Swing vs. Output Current, G = 1
–10–8–6–4–2 0 2 4 6 8 10
V
S
= ±15V
ERROR (1ppm/DIV)
OUTPUT VOLTAGE (V)
13702-023
Figure 23. Gain Nonlinearity, G = 1, RL = 10 kΩ
VS = ±15V
–10 –8 –6 –4 –2 0 2 4 6 8 10
ERROR (10ppm/DIV)
OUTPUT VOLTAGE (V)
13702-024
Figure 24. Gain Nonlinearity, G = 100, RL = 10 kΩ
V
S
= ±15V
–10–8–6–4–2 0 2 4 6 8 10
ERROR (100ppm/DIV)
OUTPUT VOLTAG E (V)
13702-025
Figure 25. Gain Nonlinearity, G = 1000, RL = 10 kΩ
VOLTAGE NOISE SPECTR
A
L DENSI
T
Y RTI (nV/
√
Hz)
1
100
10
1k
1 10 100 1k 10k 100k
FREQUENCY (Hz)
GAIN = 1
GAIN = 1000
BW LIMIT
GAIN = 10
GAIN = 100
GAIN = 1000
13702-026
Figure 26. Voltage Noise Spectral Density vs. Frequency (G = 1 to 1000)
1s/DIV2µV/DIV
13702-027
Figure 27. 0.1 Hz to 10 Hz RTI Voltage Noise (G = 1)
Enhanced Product AD8221-EP
Rev. 0 | Page 11 of 14
1s/DIV0.1µV/DIV
13702-028
Figure 28. 0.1 Hz to 10 Hz RTI Voltage Noise (G = 1000)
CURRENT NOISE SPECTR
L DENSI
Y RTI (fA/
Hz)
10
100
1k
FREQUENCY (Hz)
101 100 1k 10k
13702-029
Figure 29. Current Noise Spectral Density vs. Frequency
1s/DIV5pA/DIV
13702-030
Figure 30. 0.1 Hz to 10 Hz Current Noise
0
5
10
15
20
25
30
OUTPUT VOLTAGE (V p-p)
FREQUENCY (Hz)
1k 100k10k 1M
GAIN = 1 GAIN = 10, 100, 1000
V
S
= ±15V
13702-031
Figure 31. Large Signal Frequency Response
20µs/DIV
0.002%/DIV
7.9µs TO 0.01%
8.5µs TO 0.001%
5V/DIV
13702-032
Figure 32. Large Signal Pulse Response and Settling Time (G = 1), 0.002%/DIV
20µs/DIV
4.9µs TO 0.01%
5.6µs TO 0.001%
5V/DIV
0.002%/DIV
13702-033
Figure 33. Large Signal Pulse Response and Settling Time (G = 10),
0.002%/DIV
AD8221-EP Enhanced Product
Rev. 0 | Page 12 of 14
20µs/DIV
10.3µs TO 0.01%
13.4µs TO 0.001%
5V/DIV
0.002%/DIV
13702-034
Figure 34. Large Signal Pulse Response and Settling Time (G = 100),
0.002%/DIV
200µs/DIV
83µs TO 0.01%
112µs TO 0.001%
5V/DIV
0.002%/DIV
13702-035
Figure 35. Large Signal Pulse Response and Settling Time (G = 1000),
0.002%/DIV
4µs/DIV
20mV/DIV
13702-036
Figure 36. Small Signal Response, G = 1, RL = 2 kΩ, CL = 100 pF
4µs/DIV
20mV/DIV
13702-037
Figure 37. Small Signal Response, G = 10, RL = 2 kΩ, CL = 100 pF
10µs/DIV
20mV/DIV
13702-038
Figure 38. Small Signal Response, G = 100, RL = 2 kΩ, CL = 100 pF
100µs/DIV
20mV/DIV
13702-039
Figure 39. Small Signal Response, G = 1000, RL = 2 kΩ, CL = 100 pF
Enhanced Product AD8221-EP
Rev. 0 | Page 13 of 14
SETTLING TIME (µs)
0
10
5
15
OUTPUT VOLTAGE STEP SIZE (V)
50101520
SETTLED TO 0.01%
SETTLED TO 0.001%
13702-040
Figure 40. Settling Time vs. Output Voltage Step Size (G = 1)
SETTLING TIME (µs)
1
100
10
1000
GAIN
110010 1000
SETTLED TO 0.001%
SETTLED TO 0.01%
13702-041
Figure 41. Settling Time vs. Gain for a 10 V Step
AD8221-EP Enhanced Product
Rev. 0 | Page 14 of 14
OUTLINE DIMENSIONS
COMPLIANT TO JEDEC STANDARDS MO-187-AA
6°
0°
0.80
0.55
0.40
4
8
1
5
0.65 BSC
0.40
0.25
1.10 MAX
3.20
3.00
2.80
COPLANARITY
0.10
0.23
0.09
3.20
3.00
2.80
5.15
4.90
4.65
PIN 1
IDENTIFIER
15° MAX
0.95
0.85
0.75
0.15
0.05
10-07-2009-B
Figure 42. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
ORDERING GUIDE
Model1 Temperature Range Package Description Package Option Branding
AD8221TRMZ-EP –55°C to +125°C 8-Lead Mini Small Outline Package [MSOP] RM-8 Y67
AD8221TRMZ-EP-R7 –55°C to +125°C 8-Lead Mini Small Outline Package [MSOP] RM-8 Y67
1 Z = RoHS Compliant Part.
©2016 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D13702-0-4/16(0)