Analog Devices AD8676 Service Manual
Ultra Precision, 36 V, 2.8 nV/√Hz
p
p
FEATURES
Very low voltage noise 2.8 nV/√Hz @ 1 kHz
Rail-to-rail output swing
Low input bias current: 2 nA maximum
Very low offset voltage: 12 μV typical
Low input offset drift: 0.6 μV/°C maximum
Very high gain: 120 dB
Wide bandwidth: 10 MHz typical
±5 V to ±18 V operation
APPLICATIONS
Precision instrumentation
PLL filters
Laser diode control loops
Strain gage amplifiers
Medical instrumentation
Thermocouple amplifiers
GENERAL DESCRIPTION
The AD8676 precision operational amplifier offers ultralow
offset, drift, and voltage noise combined with very low input
bias currents over the full operating temperature range. The
AD8676 is a precision, wide bandwidth op amp featuring rail-torail output swings and very low noise. Operation is fully
specified from ±5 V to ±15 V.
The AD8676 features a rail-to-rail output like that of the OP184,
but with wide bandwidth and even lower voltage noise, combined with the precision and low power consumption like that
of the industry-standard OP07 amplifier. Unlike other low
noise, rail-to-rail op amps, the AD8676 has very low input bias
current and low input current noise.
With typical offset voltage of only 12 µV, offset drift of 0.2 µV/°C,
and noise of only 0.10 V p-p (0.1 Hz to 10 Hz), the AD8676 is
perfectly suited for applications where large error sources
cannot be tolerated. Precision instrumentation, PLL and other
precision filter circuits, position and pressure sensors, medical
Dual Rail-to-Rail Out
ut Op Am
AD8676
PIN CONFIGURATIONS
OUT A
1
AD8676
2
–IN A
+IN A
3
TOP VIEW
(Not to Scale)
V–
4
Figure 1. 8-Lead SOIC_N (R-8)
1
OUT A
2
–IN A
+IN A
AD8676
3
TOP VIEW
(Not to Scale)
4
V–
Figure 2. 8-Lead MSOP (RM-8)
instrumentation, and strain gage amplifiers benefit greatly from
the very low noise, low input bias current, and wide bandwidth.
Many systems can take advantage of the low noise, dc precision,
and rail-to-rail output swing provided by the AD8676 to maximize SNR and dynamic range.
The smaller packages and low power consumption afforded by
the AD8676 allow maximum channel density or minimum
board size for space-critical equipment.
The AD8676 is specified for the extended industrial temperature
range (−40°C to +125°C). The AD8676 is available in the 8-lead
MSOP, and the popular 8-lead, narrow SOIC; both of which are
lead-free packages. MSOP packaged devices are only available
in tape and reel format.
For the single version of this ultraprecision rail-to-rail op amp,
see the AD8675 data sheet.
8
7
6
5
8
7
6
5
V+
OUT B
–IN B
+IN B
V+
OUT B
–IN B
+IN B
06487-001
06487-002
Rev. 0
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: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2006 Analog Devices, Inc. All rights reserved.
AD8676
TABLE OF CONTENTS
Features .............................................................................................. 1
Absolute Maximum Ratings ............................................................5
Applications....................................................................................... 1
Pin Configurations ........................................................................... 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Electrical Specifications............................................................... 3
REVISION HISTORY
10/06—Revision 0: Initial Version
Thermal Resistance .......................................................................5
Power Sequencing .........................................................................5
ESD Caution...................................................................................5
Typical Perf or m an c e Charac t e r istics ..............................................6
Outline Dimensions ....................................................................... 10
Ordering Guide .......................................................................... 10
Rev. 0 | Page 2 of 12
AD8676
SPECIFICATIONS
ELECTRICAL SPECIFICATIONS
VS = ±5.0 V, VCM = 0 V, VO = 0 V, TA = +25°C, unless otherwise specified.
Table 1.
Parameter Symbol Conditions Min Typ Max Unit
INPUT CHARACTERISTICS
Offset Voltage V
OS
B Grade (SOIC) 12 50 μV
B Grade (MSOP) 60 μV
A Grade (SOIC, MSOP) 100 μV
Offset Voltage V
OS
B Grade (SOIC, MSOP) 15 160 μV
A Grade (SOIC, MSOP) 250 μV
Input Bias Current I
B
−40°C ≤ TA ≤ +125°C −5.5 +1 +5.5 nA
Input Offset Current I
OS
−40°C ≤ TA ≤ +125°C −2.8 +0.1 +2.8 nA
Input Voltage Range −3.5 +3.5 V
Common-Mode Rejection Ratio CMRR VCM = −3.0 V to +3.0 V 105 130 dB
−40°C ≤ TA ≤ +125°C 105 130 dB
Open-Loop Gain A
VO
V
−40°C ≤ TA ≤ +125°C 700 1250 V/mV
Offset Voltage Drift ΔVOS/ΔT −40°C ≤ TA ≤ +125°C 0.2 0.6 μV/°C
OUTPUT CHARACTERISTICS
Output Voltage High V
OH
−40°C ≤ TA ≤ +125°C +4.78 +4.82 V
Output Voltage Low V
OL
−40°C ≤ TA ≤ +125°C −4.93 −4.82 V
Short-Circuit Limit I
Output Current I
SC
O
POWER SUPPLY
Power Supply Rejection Ratio PSRR VS = ±5.0 V to ±15.0 V 106 120 dB
−40°C ≤ TA ≤ +125°C 106 120 dB
Supply Current/Amplifier I
SY
−40°C ≤ TA ≤ +125°C 2.7 3.4 mA
DYNAMIC PERFORMANCE
Slew Rate SR RL = 2 kΩ 2.5 V/μs
Gain Bandwidth Product GBP 10 MHz
NOISE PERFORMANCE
Voltage Noise e
Voltage Noise Density e
Current Noise Density i
n p-p
n
n
−40°C ≤ TA ≤ +125°C
−2 +0.5 +2 nA
−1 +0.1 +1 nA
RL = 2 kΩ to ground, 1000 2000 V/mV
= −3.5 V to +3.5 V
O
RL = 2 kΩ to ground +4.84 +4.86 V
RL = 2 kΩ to ground −4.95 −4.86 V
+40 mA
±20 mA
VO = 0 V 2.3 2.7 mA
0.1 Hz to 10 Hz 0.1 μV p-p
f = 1 kHz 2.8 nV/√Hz
f = 10 Hz 0.3 pA/√Hz
Rev. 0 | Page 3 of 12
AD8676
VS = ±15 V, VCM = 0 V, VO = 0 V, TA = +25°C, unless otherwise specified.
Table 2.
Parameter Symbol Conditions Min Typ Max Unit
INPUT CHARACTERISTICS
Offset Voltage V
OS
B Grade (SOIC) 12 50 μV
B Grade (MSOP) 60 μV
A Grade (SOIC, MSOP) 100 μV
Offset Voltage V
OS
B Grade (SOIC, MSOP) 15 160 μV
A Grade (SOIC, MSOP) 250 μV
Input Bias Current I
B
−40°C ≤ TA ≤ +125°C −4.5 −1 +4.5 nA
Input Offset Current I
OS
−40°C ≤ TA ≤ +125°C −2.8 −0.1 +2.8 nA
Input Voltage Range −13.5 +13.5 V
Common-Mode Rejection Ratio CMRR VCM = −12.5 V to +12.5 V 111 130 dB
−40°C ≤ TA ≤ +125°C 107 130 dB
Open-Loop Gain A
VO
V
−40°C ≤ TA ≤ +125°C 700 1700 V/mV
Offset Voltage Drift ΔVOS/ΔT −40°C ≤ TA ≤ +125°C 0.2 0.6 μV/°C
OUTPUT CHARACTERISTICS
Output Voltage High V
OH
−40°C ≤ TA ≤ +125°C +14.49 +14.59 V
Output Voltage Low V
OL
−40°C ≤ TA ≤ +125°C −14.83 −14.69 V
Short-Circuit Limit I
Output Current I
SC
O
POWER SUPPLY
Power Supply Rejection Ratio PSRR VS = ±5.0 V to ±15.0 V 106 120 dB
−40°C ≤ TA ≤ +125°C 106 120 dB
Supply Current/Amplifier I
SY
−40°C ≤ TA ≤ +125°C 2.9 3.8 mA
DYNAMIC PERFORMANCE
Slew Rate SR RL =10 kΩ 2.5 V/μs
Gain Bandwidth Product GBP 10 MHz
NOISE PERFORMANCE
Voltage Noise e
Voltage Noise Density e
Current Noise Density i
n p-p
n
n
−40°C ≤ TA ≤ +125°C
−2 −0.5 +2 nA
−1 −0.1 +1 nA
RL = 2 kΩ to ground, 1500 4000 V/mV
= −13.5 V to +13.5 V
O
RL = 2 kΩ to ground +14.65 +14.7 V
RL = 2 kΩ to ground −14.88 −14.75 V
+40 mA
±20 mA
VO = 0 V 2.5 2.9 mA
0.1 Hz to 10 Hz 0.1 μV p-p
f = 1 kHz 2.8 nV/√Hz
f = 10 Hz 0.3 pA/√Hz
Rev. 0 | Page 4 of 12
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