Data Sheet
FEATURES
Low noise: 2.7 nV/√Hz at f = 10 kHz
Low offset voltage: 250 µV max over V
CM
Offset voltage drift: 0.4 µV/°C typ and 2.3 µV/°C max
Bandwidth: 28 MHz
Rail-to-rail input/output
Unity gain stable
2.7 V to 5.5 V operation
−40°C to +125°C operation
Qualified for automotive applications
NC
1
–IN
2
+IN
3
V–
4
Low Noise,
Precision CMOS Amplifier
AD8655/AD8656
PIN CONFIGURATIONS
8
NC
V+
OUT
05304-048
OUT A
1
–IN A
2
+IN A
3
V–
4
8
V+
OUT B
05304-059
AD8655
TOP VIEW
(Not to Scale)
7
6
5
AD8656
TOP VIEW
(Not to Scale)
7
6
5
–IN B
+IN B
NC
NC = NO CONNECT
Figure 1.
AD8655
8-Lead MSOP (RM-8)
8-Lead SOIC (R-8)
Figure 2.
AD8656
8-Lead MSOP (RM-8)
8-Lead SOIC (R-8)
APPLICATIONS
ADC and DAC buffers
Audio
Industrial controls
Precision filters
Digital scales
Automotive collision avoidance
PLL filters
GENERAL DESCRIPTION
The
AD8655/AD8656
are the industry’s lowest noise, precision
CMOS amplifiers. They leverage the Analog Devices DigiTrim®
technology to achieve high dc accuracy.
The
AD8655/AD8656
provide low noise (2.7 nV/√Hz at 10 kHz),
low THD + N (0.0007%), and high precision performance
(250 µV max over V
CM
) to low voltage applications. The ability
to swing rail-to-rail at the input and output enables designers
to buffer analog-to-digital converters (ADCs) and other wide
dynamic range devices in single-supply systems.
The high precision performance of the
AD8655/AD8656
improves
the resolution and dynamic range in low voltage applications.
Audio applications, such as microphone pre-amps and audio
mixing consoles, benefit from the low noise, low distortion, and
high output current capability of the
AD8655/AD8656
to reduce
system level noise performance and maintain audio fidelity. The
high precision and rail-to-rail input and output of the
AD8655/
AD8656
benefit data acquisition, process controls, and PLL
filter applications.
The
AD8655/AD8656
are fully specified over the −40°C to
+125°C temperature range. The
AD8655/AD8656
are available
in Pb-free, 8-lead MSOP and SOIC packages. The
AD8655/
AD8656
are both available for automotive applications.
Rev. E
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. 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.
Document Feedback
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 ©2005–2013 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
AD8655/AD8656
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Pin Configurations ........................................................................... 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
ESD Caution .................................................................................. 5
Typical Performance Characteristics ............................................. 6
Theory of Operation ...................................................................... 15
Applications Information .............................................................. 16
Data Sheet
Input Overvoltage Protection ................................................... 16
Input Capacitance ...................................................................... 16
Driving Capacitive Loads .......................................................... 16
Layout, Grounding, and Bypassing Considerations .................. 18
Power Supply Bypassing ............................................................ 18
Grounding ................................................................................... 18
Leakage Currents ........................................................................ 18
Outline Dimensions ....................................................................... 19
Ordering Guide............................................................................... 19
Automotive Products ................................................................. 19
REVISION HISTORY
10/13—Rev. D to Rev. E
Changes to Figure 1 Caption and Figure 2 Caption .................... 1
Deleted Figure 3 and Figure 4; Renumbered Sequentially ......... 1
Change to General Description Section ........................................ 1
Change to Figure 4 ........................................................................... 6
Change to Figure 32 ....................................................................... 10
Changes to Ordering Guide .......................................................... 19
Changes to Automotive Products Section................................... 19
6/13—Rev. C to Rev. D
Change to Figure 57 ....................................................................... 16
5/13—Rev. B to Rev. C
Change to Figure 57 ....................................................................... 16
9/11—Rev. A to Rev. B
Changes to Features Section............................................................ 1
Updated Outline Dimensions ....................................................... 19
Changes to Ordering Guide .......................................................... 19
Added Automotive Products Section .......................................... 19
6/05—Rev. 0 to Rev. A
Added AD8656 ................................................................... Universal
Added Figure 2 and Figure 4 ...........................................................1
Changes to Specifications .................................................................3
Changed Caption of Figure 12 and Added Figure 13 ...................7
Replaced Figure 16 ............................................................................7
Changed Caption of Figure 37 and Added Figure 38 ................ 11
Replaced Figure 47 ......................................................................... 13
Added Figure 55 ............................................................................. 14
Changes to Ordering Guide .......................................................... 18
4/05—Revision 0: Initial Version
Rev. E | Page 2 of 20
Data Sheet
SPECIFICATIONS
V
S
= 5.0 V, V
CM
= V
S
/2, T
A
= 25°C, unless otherwise specified.
Table 1.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Offset Voltage Drift
Input Bias Current
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
Large Signal Voltage Gain
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Current
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
INPUT CAPACITANCE
Differential
Common-Mode
NOISE PERFORMANCE
Input Voltage Noise Density
Total Harmonic Distortion + Noise
FREQUENCY RESPONSE
Gain Bandwidth Product
Slew Rate
Settling Time
Phase Margin
Symbol
V
OS
ΔV
OS
/ΔT
I
B
I
OS
−40°C ≤ T
A
≤ +125°C
CMRR
A
VO
V
CM
= 0 V to 5 V
V
O
= 0.2 V to 4.8 V, R
L
= 10 kΩ, V
CM
= 0 V
−40°C ≤ T
A
≤ +125°C
I
L
= 1 mA; −40°C ≤ T
A
≤ +125°C
I
L
= 1 mA; −40°C ≤ T
A
≤ +125°C
V
OUT
= ±0.5 V
V
S
= 2.7 V to 5.0 V
V
O
= 0 V
−40°C ≤ T
A
≤ +125°C
0
85
100
95
4.97
Conditions
V
CM
= 0 V to 5 V
−40°C ≤ T
A
≤ +125°C
−40°C ≤ T
A
≤ +125°C
−40°C ≤ T
A
≤ +125°C
Min
AD8655/AD8656
Typ
50
0.4
1
Max
250
550
2.3
10
500
10
500
5
Unit
µV
µV
µV/°C
pA
pA
pA
pA
V
dB
dB
dB
V
mV
mA
dB
mA
mA
pF
pF
nV/√Hz
nV/√Hz
%
MHz
V/µs
ns
degrees
100
110
V
OH
V
OL
I
OUT
PSRR
I
SY
C
IN
4.991
8
±220
105
3.7
30
88
4.5
5.3
9.3
16.7
e
n
THD + N
GBP
SR
ts
f = 1 kHz
f = 10 kHz
G = 1, R
L
= 1 kΩ, f = 1 kHz, V
IN
= 2 V p-p
4
2.7
0.0007
28
11
370
69
R
L
= 10 kΩ
To 0.1%, V
IN
= 0 V to 2 V step, G = +1
C
L
= 0 pF
Rev. E | Page 3 of 20
AD8655/AD8656
V
S
= 2.7 V, V
CM
= V
S
/2, T
A
= 25°C, unless otherwise specified.
Table 2.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Offset Voltage Drift
Input Bias Current
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
Large Signal Voltage Gain
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Current
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
INPUT CAPACITANCE
Differential
Common-Mode
NOISE PERFORMANCE
Input Voltage Noise Density
Total Harmonic Distortion + Noise
FREQUENCY RESPONSE
Gain Bandwidth Product
Slew Rate
Settling Time
Phase Margin
Symbol
V
OS
ΔV
OS
/ΔT
I
B
I
OS
−40°C ≤ T
A
≤ +125°C
CMRR
A
VO
V
CM
= 0 V to 2.7 V
V
O
= 0.2 V to 2.5 V, R
L
= 10 kΩ, V
CM
= 0 V
−40°C ≤ T
A
≤ +125°C
I
L
= 1 mA; −40°C ≤ T
A
≤ +125°C
I
L
= 1 mA; −40°C ≤ T
A
≤ +125°C
V
OUT
= ±0.5 V
V
S
= 2.7 V to 5.0 V
V
O
= 0 V
−40°C ≤ T
A
≤ +125°C
0
80
98
90
2.67
98
Conditions
V
CM
= 0 V to 2.7 V
−40°C ≤ T
A
≤ +125°C
−40°C ≤ T
A
≤ +125°C
−40°C ≤ T
A
≤ +125°C
Min
Typ
44
0.4
1
Data Sheet
Max
250
550
2.0
10
500
10
500
2.7
Unit
µV
µV
µV/°C
pA
pA
pA
pA
V
dB
dB
dB
V
mV
mA
dB
mA
mA
pF
pF
nV/√Hz
nV/√Hz
%
MHz
V/µs
ns
degrees
V
OH
V
OL
I
OUT
PSRR
I
SY
C
IN
2.688
10
±75
105
3.7
30
88
4.5
5.3
9.3
16.7
e
n
THD + N
GBP
SR
ts
f = 1 kHz
f = 10 kHz
G = 1, R
L
= 1kΩ, f = 1 kHz, V
IN
= 2 V p-p
4.0
2.7
0.0007
27
8.5
370
54
R
L
= 10 kΩ
To 0.1%, V
IN
= 0 to 1 V step, G = +1
C
L
= 0 pF
Rev. E | Page 4 of 20
Data Sheet
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
Supply Voltage
Input Voltage
Differential Input Voltage
Output Short-Circuit Duration
to GND
Electrostatic Discharge (HBM)
Storage Temperature Range
R, RM Packages
Junction Temperature Range
R, RM Packages
Lead Temperature
(Soldering, 10 sec)
Rating
6V
VSS − 0.3 V to VDD + 0.3 V
±6 V
Indefinite
3.0 kV
−65°C to +150°C
−65°C to +150°C
260°C
AD8655/AD8656
Table 4.
Package Type
8-Lead MSOP (RM)
8-Lead SOIC (R)
1
θ
JA1
210
158
θ
JC
45
43
Unit
°C/W
°C/W
θ
JA
is specified for worst-case conditions; that is, θ
JA
is specified for a device
soldered in the circuit board for surface-mount packages.
ESD CAUTION
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 indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Rev. E | Page 5 of 20
