Zero-Drift, Single-Supply, Rail-to-Rail
Input/Output Operational Amplifier
Data Sheet AD8629-EP
Rev. A Document Feedback
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FEATURES
Lowest auto-zero amplifier noise
Low offset voltage: 1 μV typical
Input offset drift: 0.002 μV/°C typical
Rail-to-rail input and output swing
5 V single-supply operation
High gain, CMRR, and PSRR: 130 dB
Very low input bias current: 100 pA maximum
Low supply current: 1.0 mA
Overload recovery time: 50 μs
No external components required
ENHANCED PRODUCT FEATURES
Supports defense and aerospace applications (AQEC standard)
Extended 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
Pressure and position sensors
Strain gage amplifiers
Medical instrumentation
Thermocouple amplifiers
Precision current sensing
Photodiode amplifiers
PIN CONFIGURATION
OUT A
1
–IN A
2
+IN A
3
V–
4
V+
8
OUT B
7
–IN B
6
+IN B
5
AD8629-EP
TOP VIEW
(Not to Scale)
12890-001
Figure 1. 8-Lead SOIC_N (R-8)
GENERAL DESCRIPTION
The AD8629-EP amplifier has ultralow offset, drift, and bias
current. The device is a wide bandwidth auto-zero amplifier
featuring rail-to-rail input and output swing and low noise.
Operation is fully specified from 2.7 V to 5 V single supply
(±1.35 V to ±2.5 V dual supply).
The AD8629-EP provides benefits previously found only in
expensive auto-zeroing or chopper-stabilized amplifiers. Using
Analog Devices, Inc., topology, this zero-drift amplifier
combines low cost with high accuracy and low noise. No
external capacitor is required. In addition, the AD8629-EP
greatly reduces the digital switching noise found in most
chopper-stabilized amplifiers.
With an offset voltage of only 1 µV, drift of less than 0.05 V/°C,
and noise of only 0.5 µV p-p (0 Hz to 10 Hz), the AD8629-EP is
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 the
operating temperature range. Many systems can take advantage
of the rail-to-rail input and output swings provided by the
AD8629-EP to reduce input biasing complexity and maximize
SNR.
The AD8629-EP is specified for the extended industrial
temperature range (−55°C to +125°C). The AD8629-EP is
available in a standard 8-lead narrow SOIC plastic package.
AD8629-EP Data Sheet
Rev. A | Page 2 of 8
TABLE OF CONTENTS
Features .............................................................................................. 1
Enhanced Product Features ............................................................ 1
Applications ....................................................................................... 1
Pin Configuration ............................................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Electrical Characteristics—VS = 5.0 V ....................................... 3
Electrical Characteristics—VS = 2.7 V........................................4
Absolute Maximum Ratings ............................................................5
Thermal Characteristics ...............................................................5
ESD Caution...................................................................................5
Typical Performance Characteristics ..............................................6
Outline Dimensions ..........................................................................8
Ordering Guide .............................................................................8
REVISION HISTORY
8/15—Rev. 0 to Rev. A
Changes to Ordering Guide ............................................................ 8
6/15—Revision 0: Initial Version
Data Sheet AD8629-EP
Rev. A | Page 3 of 8
SPECIFICATIONS
ELECTRICAL CHARACTERISTICS—VS = 5.0 V
VS = 5.0 V, VCM = 2.5 V, TA = 25°C, unless otherwise noted.
Table 1.
Parameter Symbol Test Conditions/Comments Min Typ Max Unit
INPUT CHARACTERISTICS
Offset Voltage VOS
1 5 µV
−55°C ≤ TA ≤ +125°C
15 µV
Input Bias Current IB
30 100 pA
−55°C ≤ TA ≤ +125°C
1.5 nA
Input Offset Current IOS
50 200 pA
−55°C ≤ TA ≤ +125°C
250 pA
Input Voltage Range
0
5 V
Common-Mode Rejection Ratio CMRR VCM = 0 V to 5 V 120 140
dB
−55°C ≤ TA ≤ +125°C 115 130
dB
Large Signal Voltage Gain AVO RL = 10 kΩ, VO = 0.3 V to 4.7 V 125 145
dB
−55°C ≤ TA ≤ +125°C 120 135
dB
Offset Voltage Drift ∆VOS/∆T −55°C ≤ TA ≤ +125°C
0.008 0.05 µV/°C
OUTPUT CHARACTERISTICS
Output Voltage High VOH RL = 100 kΩ to ground 4.99 4.996
V
−55°C ≤ TA ≤ +125°C 4.99 4.995
V
RL = 10 kΩ to ground 4.95 4.98
V
−55°C ≤ TA ≤ +125°C 4.95 4.97
V
Output Voltage Low VOL RL = 100 kΩ to V+
1 5 mV
−55°C ≤ TA ≤ +125°C
2 5 mV
RL = 10 kΩ to V+
10 20 mV
−55°C ≤ TA ≤ +125°C
15 20 mV
Short-Circuit Limit ISC
±25 ±50
mA
−55°C ≤ TA ≤ +125°C
±40
mA
Output Current IO
±30
mA
−55°C ≤ TA ≤ +125°C
±15
mA
POWER SUPPLY
Power Supply Rejection Ratio PSRR VS = 2.7 V to 5.5 V, −55°C ≤ TA ≤ +125°C 115 130
dB
Supply Current per Amplifier ISY VO = VS/2 0.85 1.1 mA
−55°C ≤ TA ≤ +125°C
1.0 1.2 mA
INPUT CAPACITANCE CIN
Differential
1.5
pF
Common Mode
8.0
pF
DYNAMIC PERFORMANCE
Slew Rate SR RL = 10 kΩ
1.0
V/µs
Overload Recovery Time
0.05
ms
Gain Bandwidth Product
GBP
2.5
MHz
NOISE PERFORMANCE
Voltage Noise
e
n
p-p
0.1 Hz to 10 Hz
0.5
µV p-p
0.1 Hz to 1.0 Hz
0.16
µV p-p
Voltage Noise Density en f = 1 kHz
22
nV/√Hz
Current Noise Density in f = 10 Hz
5
fA/√Hz
AD8629-EP Data Sheet
Rev. A | Page 4 of 8
ELECTRICAL CHARACTERISTICS—VS = 2.7 V
VS = 2.7 V, VCM = 1.35 V, VO = 1.4 V, TA = 25°C, unless otherwise noted.
Table 2.
Parameter Symbol Test Conditions/Comments Min Typ Max Unit
INPUT CHARACTERISTICS
Offset Voltage VOS 1 5 µV
−55°C ≤ TA ≤ +125°C 15 µV
Input Bias Current IB 30 100 pA
−55°C ≤ TA ≤ +125°C 1.0 1.5 nA
Input Offset Current IOS 50 200 pA
−55°C ≤ TA ≤ +125°C 250 pA
Input Voltage Range 0 2.7 V
Common-Mode Rejection Ratio CMRR VCM = 0 V to 2.7 V 115 130 dB
−55°C ≤ TA ≤ +125°C 110 120 dB
Large Signal Voltage Gain AVO RL = 10 kΩ, VO = 0.3 V to 2.4 V 110 140 dB
−55°C ≤ TA ≤ +125°C 105 130 dB
Offset Voltage Drift ∆VOS/∆T −55°C ≤ TA ≤ +125°C 0.002 0.05 µV/°C
OUTPUT CHARACTERISTICS
Output Voltage High VOH RL = 100 kΩ to ground 2.68 2.695 V
−55°C ≤ TA ≤ +125°C 2.68 2.695 V
RL = 10 kΩ to ground 2.67 2.68 V
−55°C ≤ TA ≤ +125°C 2.67 2.675 V
Output Voltage Low VOL RL = 100 kΩ to V+ 1 5 mV
−55°C ≤ TA ≤ +125°C 2 5 mV
RL = 10 kΩ to V+ 10 20 mV
−55°C ≤ TA ≤ +125°C 15 20 mV
Short-Circuit Limit ISC ±10 ±15 mA
−55°C ≤ TA ≤ +125°C ±10 mA
Output Current IO ±10 mA
−55°C ≤ TA ≤ +125°C ±5 mA
POWER SUPPLY
Power Supply Rejection Ratio
PSRR
V
S
= 2.7 V to 5.5 V, −55°C ≤ T
A
≤ +125°C
115
130
dB
Supply Current per Amplifier ISY VO = VS/2 0.75 1.0 mA
−55°C ≤ TA ≤ +125°C 0.9 1.2 mA
INPUT CAPACITANCE CIN
Differential 1.5 pF
Common Mode 8.0 pF
DYNAMIC PERFORMANCE
Slew Rate SR RL = 10 kΩ 1 V/µs
Overload Recovery Time 0.05 ms
Gain Bandwidth Product GBP 2 MHz
NOISE PERFORMANCE
Voltage Noise en p-p 0.1 Hz to 10 Hz 0.5 µV p-p
Voltage Noise Density en f = 1 kHz 22 nV/√Hz
Current Noise Density in f = 10 Hz 5 fA/√Hz
Data Sheet AD8629-EP
Rev. A | Page 5 of 8
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter Rating
Supply Voltage 6 V
Input Voltage
S
Differential Input Voltage1 ±5.0 V
Output Short-Circuit Duration to GND Indefinite
Storage Temperature Range −65°C to +150°C
Operating Temperature Range −55°C to +125°C
Junction Temperature Range −65°C to +150°C
Lead Temperature (Soldering, 60 sec) 300°C
ESD
HBM 8-Lead SOIC_N ±4000 V
FICDM 8-Lead SOIC_N ±1250 V
1 The differential input voltage is limited to ±5 V or the supply voltage,
whichever is less.
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
θJA is specified for worst-case conditions, that is, θJA is specified
for the device soldered in a circuit board for surface-mount
packages. This was measured using a standard two-layer board.
Table 4.
Package Type
θ
JA
θ
JC
Unit
8-Lead SOIC_N (R-8) 158 43 °C/W
ESD CAUTION
AD8629-EP Data Sheet
Rev. A | Page 6 of 8
TYPICAL PERFORMANCE CHARACTERISTICS
+85°C
+25°C
–40°C
V
S
= 5V
INPUT COMMON-MODE VOLTAGE (V)
INPUT BIAS CURRENT (pA)
60
40
50
30
10
20
0
0123456
12890-002
Figure 2. Input Bias Current vs. Input Common-Mode Voltage
12890-003
OUTPUT SHORT-CIRCUIT CURRENT (mA)
TEMPERATURE (°C)
–150
–100
–50
0
+50
+100
+150
–75 –25 +25 +75 +125
+I
SC
–I
SC
V
S
= 2.7V
Figure 3. Output Short-Circuit Current vs. Temperature (2.7 V)
12890-004
OUTPUT-TO-RAIL VOLTAGE (mV)
TEMPERATURE (°C)
0.1
1
10
100
1k
–75 –25 +25 +75 +125
V
CC
– V
OH
@ 10kΩ
V
OL
– V
EE
@ 10kΩ
V
CC
– V
OH
@ 1kΩ
V
OL
– V
EE
@ 1kΩ
V
CC
– V
OH
@ 100kΩ
V
OL
– V
EE
@ 100kΩ
V
S
= 2.7V
Figure 4. Output-to-Rail Voltage vs. Temperature (2.7 V)
12890-005
INPUT BIAS CURRENT (pA)
TEMPERATURE (°C)
–75 –25 +25 +75 +125
0
100
200
300
400
500
600
700
V
S
= 5V
Figure 5. Input Bias Current vs. Temperature
12890-006
TEMPERATURE (°C)
–75 –25 +25 +75 +125
–150
–100
–50
0
+50
+100
+150
OUTPUT SHORT-CIRCUIT CURRENT (mA)
+I
SC
–I
SC
V
S
= 5V
Figure 6. Output Short-Circuit Current vs. Temperature (5 V)
12890-007
OUTPUT-TO-RAIL VOLTAGE (mV)
TEMPERATURE (°C)
0.1
1
10
100
1k
–75 –25 +25 +75 +125
V
S
= 5V
V
CC
– V
OH
@ 10kΩ
V
OL
– V
EE
@ 10kΩ
V
CC
– V
OH
@ 1kΩ
V
OL
– V
EE
@ 1kΩ
V
CC
– V
OH
@ 100kΩ
V
OL
– V
EE
@ 100kΩ
Figure 7. Output-to-Rail Voltage vs. Temperature (5 V)
Data Sheet AD8629-EP
Rev. A | Page 7 of 8
12890-008
NUMBER OF AMPLIFIERS
TCV
OS
(nV/C)
0
2
4
6
8
10
12
14
16
18
–6 –4 –2 +20+4+6+8+12+10 +16 +18+14 +20
V
S
= 5V
T
A
= –55°C TO +125°C
V
CM
= 2.5V
Figure 8. Input Offset Voltage Drift Distribution
12890-009
POWER SUPPLY REJECTION (dB)
TEMPERATURE (°C)
50
60
70
80
90
100
110
120
130
140
–75 –25 +25 +75 +125
VS = 2.7V TO 5V
Figure 9. Power Supply Rejection vs. Temperature
12890-010
SUPPLY CURRENT (µA)
TEMPERATURE (°C)
–75 –25 +25 +75 +125
0
100
200
300
400
500
600
700
800
900
V
S
= 2.7V
V
S
= 5V
Figure 10. Supply Current vs. Temperature
AD8629-EP Data Sheet
Rev. A | Page 8 of 8
OUTLINE DIMENSIONS
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
COMPLIANT TO JEDEC STANDARDS MS-012-AA
012407-A
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
0.50 (0.0196)
0.25 (0.0099) 45°
8°
0°
1.75 (0.0688)
1.35 (0.0532)
SEATING
PLANE
0.25 (0.0098)
0.10 (0.0040)
4
1
8 5
5.00(0.1968)
4.80(0.1890)
4.00 (0.1574)
3.80 (0.1497)
1.27 (0.0500)
BSC
6.20 (0.2441)
5.80 (0.2284)
0.51 (0.0201)
0.31 (0.0122)
COPLANARITY
0.10
Figure 11. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model1 Temperature Range Package Description Package Option
AD8629TRZ-EP −55°C to +125°C 8-Lead Standard Small Outline Package [SOIC_N] R-8
AD8629TRZ-EP-R7 −55°C to +125°C 8-Lead Standard Small Outline Package [SOIC_N] R-8
1 Z = RoHS Compliant Part.
©2002–2015 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D12890-0-8/15(A)