Low Cost CMOS, High Speed,
Rail-to-Rail Amplifiers
ADA4891-1/ADA4891-2/ADA4891-3/ADA4891-4
FEATURES
High speed and fast settling
−3 dB bandwidth: 220 MHz (G = +1)
Slew rate: 170 V/μs
Settling time to 0.1%: 28 ns
Video specifications (G = +2, R
L
= 150 Ω)
0.1 dB gain flatness: 25 MHz
Differential gain error: 0.05%
Differential phase error: 0.25°
Single-supply operation
Wide supply range: 2.7 V to 5.5 V
Output swings to within 50 mV of supply rails
Low distortion: 79 dBc SFDR at 1 MHz
Linear output current: 125 mA at −40 dBc
Low power: 4.4 mA per amplifier
CONNECTION DIAGRAMS
ADA4891-1
NC
1
–IN
2
8
7
6
5
NC
+V
S
OUT
08054-026
08054-001
+IN
3
–V
S 4
NC
NC = NO CONNECT
Figure 1. 8-Lead SOIC_N (R-8)
ADA4891-1
OUT
1
–V
S 2
+IN
3
4
5
+V
S
–IN
Figure 2. 5-Lead SOT-23 (RJ-5)
APPLICATIONS
Imaging
Consumer video
Active filters
Coaxial cable drivers
Clock buffers
Photodiode preamp
Contact image sensor and buffers
OUT1
1
–IN1
2
+IN1
3
–V
S 4
ADA4891-2
8
7
6
5
+V
S
OUT2
–IN2
08054-027
08054-074
+IN2
NC = NO CONNECT
Figure 3. 8-Lead SOIC_N (R-8) and 8-Lead MSOP (RM-8)
ADA4891-3
PD1
1
PD2
2
PD3
3
+V
S 4
+IN1
5
–IN1
6
OUT1
7
14
13
12
11
10
9
8
GENERAL DESCRIPTION
The ADA4891-1 (single), ADA4891-2 (dual), ADA4891-3 (triple),
and ADA4891-4 (quad) are CMOS, high speed amplifiers that
offer high performance at a low cost. The amplifiers feature true
single-supply capability, with an input voltage range that extends
300 mV below the negative rail.
In spite of their low cost, the ADA4891 family provides high
performance and versatility. The rail-to-rail output stage enables
the output to swing to within 50 mV of each rail, enabling maxi-
mum dynamic range.
The ADA4891 family of amplifiers is ideal for imaging applica-
tions, such as consumer video, CCD buffers, and contact image
sensor and buffers. Low distortion and fast settling time also
make them ideal for active filter applications.
The ADA4891-1/ADA4891-2/ADA4891-3/ADA4891-4 are avail-
able in a wide variety of packages. The ADA4891-1 is available
in 8-lead SOIC and 5-lead SOT-23 packages. The ADA4891-2
is available in 8-lead SOIC and 8-lead MSOP packages. The
ADA4891-3 and ADA4891-4 are available in 14-lead SOIC and
14-lead TSSOP packages. The amplifiers are specified to operate
over the extended temperature range of −40°C to +125°C.
Rev. B
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.
OUT2
–IN2
+IN2
–V
S
+IN3
–IN3
OUT3
08054-073
Figure 4. 14-Lead SOIC_N (R-14) and 14-Lead TSSOP (RU-14)
ADA4891-4
OUT1
1
–IN1
2
+IN1
3
14
13
12
11
10
9
8
OUT4
–IN4
+IN4
–V
S
+IN3
–IN3
OUT3
+V
S 4
+IN2
5
–IN2
6
OUT2
7
Figure 5. 14-Lead SOIC_N (R-14) and 14-Lead TSSOP (RU-14)
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
©2010 Analog Devices, Inc. All rights reserved.
ADA4891-1/ADA4891-2/ADA4891-3/ADA4891-4
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
General Description ......................................................................... 1
Connection Diagrams ...................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
5 V Operation ............................................................................... 3
3 V Operation ............................................................................... 4
Absolute Maximum Ratings............................................................ 6
Maximum Power Dissipation ..................................................... 6
ESD Caution .................................................................................. 6
Typical Performance Characteristics ............................................. 7
Applications Information .............................................................. 15
Using the ADA4891 ................................................................... 15
Wideband, Noninverting Gain Operation .............................. 15
Wideband, Inverting Gain Operation ..................................... 15
Recommended Values ............................................................... 15
Effect of R
F
on 0.1 dB Gain Flatness ........................................ 16
Driving Capacitive Loads .......................................................... 17
Terminating Unused Amplifiers .............................................. 18
Disable Feature (ADA4891-3 Only) ........................................ 18
Single-Supply Operation ........................................................... 18
Video Reconstruction Filter ...................................................... 19
Multiplexer .................................................................................. 19
Layout, Grounding, and Bypassing .............................................. 20
Power Supply Bypassing ............................................................ 20
Grounding ................................................................................... 20
Input and Output Capacitance ................................................. 20
Input-to-Output Coupling ........................................................ 20
Leakage Currents ........................................................................ 20
Outline Dimensions ....................................................................... 21
Ordering Guide .......................................................................... 23
REVISION HISTORY
7/10—Rev. A to Rev. B
Added ADA4891-3 and ADA4891-4 ............................... Universal
Added 14-Lead SOIC and 14-Lead TSSOP Packages .... Universal
Deleted Figure 4; Renumbered Figures Sequentially ................... 1
Changes to Features Section and General Description Section . 1
Added Figure 4 and Figure 5 ........................................................... 1
Changes to Table 1 ............................................................................ 3
Changes to Table 2 ............................................................................ 4
Changes to Maximum Power Dissipation Section
and Figure 6 ....................................................................................... 6
Added Table 4; Renumbered Tables Sequentially ........................ 6
Deleted Figure 11 .............................................................................. 6
Changes to Typical Performance Characteristics Section ........... 7
Deleted Figure 12 .............................................................................. 7
Changes to Wideband, Noninverting Gain Operation Section,
Wideband, Inverting Gain Operation Section, and Table 5 ..... 15
Added Table 6.................................................................................. 16
Changes to Figure 52...................................................................... 16
Added Figure 53 ............................................................................. 16
Changed Layout of Driving Capacitive Loads Section.............. 17
Added Disable Feature (ADA4891-3 Only) Section
and Single-Supply Operation Section .......................................... 18
Added Multiplexer Section ........................................................... 19
Updated Outline Dimensions ....................................................... 21
Changes to Ordering Guide .......................................................... 23
6/10—Rev. 0 to Rev. A
Changes to Figure 26.........................................................................9
Changes to Figure 33 and Figure 34............................................. 10
Updated Outline Dimensions ....................................................... 18
Changes to Ordering Guide .......................................................... 18
2/10—Revision 0: Initial Version
Rev. B | Page 2 of 24
ADA4891-1/ADA4891-2/ADA4891-3/ADA4891-4
SPECIFICATIONS
5 V OPERATION
T
A
= 25°C, V
S
= 5 V, R
L
= 1 kΩ to 2.5 V, unless otherwise noted. All specifications are for the ADA4891-1, ADA4891-2, ADA4891-3, and
ADA4891-4, unless otherwise noted. For the ADA4891-1 and ADA4891-2, R
F
= 604 Ω; for the ADA4891-3 and ADA4891-4, R
F
= 453 Ω,
unless otherwise noted.
Table 1.
Parameter
DYNAMIC PERFORMANCE
−3 dB Small-Signal Bandwidth
Test Conditions/Comments
ADA4891-1/ADA4891-2, G = +1, V
O
= 0.2 V p-p
ADA4891-3/ADA4891-4, G = +1, V
O
= 0.2 V p-p
ADA4891-1/ADA4891-2, G = +2, V
O
= 0.2 V p-p,
R
L
= 150 Ω to 2.5 V
ADA4891-3/ADA4891-4, G = +2, V
O
= 0.2 V p-p,
R
L
= 150 Ω to 2.5 V
ADA4891-1/ADA4891-2, G = +2, V
O
= 2 V p-p,
R
L
= 150 Ω to 2.5 V, R
F
= 604 Ω
ADA4891-3/ADA4891-4, G = +2, V
O
= 2 V p-p,
R
L
= 150 Ω to 2.5 V, R
F
= 374 Ω
G = +2, V
O
= 2 V step, 10% to 90%
G = +2, V
O
= 2 V p-p, R
L
= 150 Ω
G = +2, V
O
= 2 V step
f
C
= 1 MHz, V
O
= 2 V p-p, G = +1
f
C
= 1 MHz, V
O
= 2 V p-p, G = −1
f = 1 MHz
G = +2, R
L
= 150 Ω to 2.5 V
G = +2, R
L
= 150 Ω to 2.5 V
f = 5 MHz, G = +2, V
O
= 2 V p-p
Min
Typ
240
220
90
96
25
25
170/210
40
28
−79/−93
−75/−91
9
0.05
0.25
−80
±2.5
±3.1
6
+2
83
71
5
3.2
−V
S
− 0.3 to
+V
S
− 0.8
88
0.01 to 4.98
0.08 to 4.90
125
205
307
ADA4891-3 only
Part enabled
Part powered down
Rev. B | Page 3 of
24
Max
Unit
MHz
MHz
MHz
MHz
MHz
MHz
V/μs
MHz
ns
dBc
dBc
nV/√Hz
%
Degrees
dB
Bandwidth for 0.1 dB Gain Flatness
Slew Rate, t
R
/t
F
−3 dB Large-Signal Frequency Response
Settling Time to 0.1%
NOISE/DISTORTION PERFORMANCE
Harmonic Distortion, HD2/HD3
Input Voltage Noise
Differential Gain Error (NTSC)
Differential Phase Error (NTSC)
All-Hostile Crosstalk
DC PERFORMANCE
Input Offset Voltage
Offset Drift
Input Bias Current
Open-Loop Gain
INPUT CHARACTERISTICS
Input Resistance
Input Capacitance
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio (CMRR)
OUTPUT CHARACTERISTICS
Output Voltage Swing
Output Current
Short-Circuit Current
Sourcing
Sinking
POWER-DOWN PINS (PD1, PD2, PD3)
Threshold Voltage, V
TH
Bias Current
±10
T
MIN
to T
MAX
−50
77
+50
R
L
= 1 kΩ to 2.5 V
R
L
= 150 Ω to 2.5 V
mV
mV
μV/°C
pA
dB
dB
GΩ
pF
V
dB
V
V
mA
mA
mA
V
nA
μA
V
CM
= 0 V to 3.0 V
R
L
= 1 kΩ to 2.5 V
R
L
= 150 Ω to 2.5 V
1% THD with 1 MHz, V
O
= 2 V p-p
2.4
65
−22
ADA4891-1/ADA4891-2/ADA4891-3/ADA4891-4
Parameter
Turn-On Time
Turn-Off Time
POWER SUPPLY
Operating Range
Quiescent Current per Amplifier
Supply Current When Powered Down
Power Supply Rejection Ratio (PSRR)
Positive PSRR
Negative PSRR
OPERATING TEMPERATURE RANGE
Test Conditions/Comments
Part enabled, output rises to 90% of final value
Part powered down, output falls to 10% of final
value
Min
Typ
166
49
Max
Unit
ns
ns
2.7
ADA4891-3 only
+V
S
= 5 V to 5.25 V, −V
S
= 0 V
+V
S
= 5 V, −V
S
= −0.25 V to 0 V
−40
4.4
0.8
65
63
5.5
V
mA
mA
dB
dB
°C
+125
3 V OPERATION
T
A
= 25°C, V
S
= 3 V, R
L
= 1 kΩ to 1.5 V, unless otherwise noted. All specifications are for the ADA4891-1, ADA4891-2, ADA4891-3, and
ADA4891-4, unless otherwise noted. For the ADA4891-1 and ADA4891-2, R
F
= 604 Ω; for the ADA4891-3 and ADA4891-4, R
F
= 453 Ω,
unless otherwise noted.
Table 2.
Parameter
DYNAMIC PERFORMANCE
−3 dB Small-Signal Bandwidth
Test Conditions/Comments
ADA4891-1/ADA4891-2, G = +1, V
O
= 0.2 V p-p
ADA4891-3/ADA4891-4, G = +1, V
O
= 0.2 V p-p
ADA4891-1/ADA4891-2, G = +2, V
O
= 0.2 V p-p,
R
L
= 150 Ω to 1.5 V
ADA4891-3/ADA4891-4, G = +2, V
O
= 0.2 V p-p,
R
L
= 150 Ω to 1.5 V
ADA4891-1/ADA4891-2, G = +2, V
O
= 2 V p-p,
R
L
= 150 Ω to 1.5 V, R
F
= 604 Ω
ADA4891-3/ADA4891-4, G = +2, V
O
= 2 V p-p,
R
L
= 150 Ω to 1.5 V, R
F
= 374 Ω
G = +2, V
O
= 2 V step, 10% to 90%
G = +2, V
O
= 2 V p-p, R
L
= 150 Ω
G = +2, V
O
= 2 V step
f
C
= 1 MHz, V
O
= 2 V p-p, G = −1
f = 1 MHz
G = +2, R
L
= 150 Ω to 0.5 V, +V
S
= 2 V, −V
S
= −1 V
G = +2, R
L
= 150 Ω to 0.5 V, +V
S
= 2 V, −V
S
= −1 V
f = 5 MHz, G = +2
Min
Typ
190
175
75
80
18
18
140/230
40
30
−70/−89
9
0.23
0.77
−80
±2.5
±3.1
6
+2
76
65
5
3.2
−V
S
− 0.3 to
+V
S
− 0.8
87
±10
Max
Unit
MHz
MHz
MHz
MHz
MHz
MHz
V/μs
MHz
ns
dBc
nV/√Hz
%
Degrees
dB
mV
mV
μV/°C
pA
dB
dB
GΩ
pF
V
dB
Bandwidth for 0.1 dB Gain Flatness
Slew Rate, t
R
/t
F
−3 dB Large-Signal Frequency Response
Settling Time to 0.1%
NOISE/DISTORTION PERFORMANCE
Harmonic Distortion, HD2/HD3
Input Voltage Noise
Differential Gain Error (NTSC)
Differential Phase Error (NTSC)
All-Hostile Crosstalk
DC PERFORMANCE
Input Offset Voltage
Offset Drift
Input Bias Current
Open-Loop Gain
INPUT CHARACTERISTICS
Input Resistance
Input Capacitance
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio (CMRR)
T
MIN
to T
MAX
−50
72
+50
R
L
= 1 kΩ to 1.5 V
R
L
= 150 Ω to 1.5 V
V
CM
= 0 V to 1.5 V
Rev. B | Page 4 of
24
ADA4891-1/ADA4891-2/ADA4891-3/ADA4891-4
Parameter
OUTPUT CHARACTERISTICS
Output Voltage Swing
Output Current
Short-Circuit Current
Sourcing
Sinking
POWER-DOWN PINS (PD1, PD2, PD3)
Threshold Voltage, V
TH
Bias Current
Turn-On Time
Turn-Off Time
POWER SUPPLY
Operating Range
Quiescent Current per Amplifier
Supply Current When Powered Down
Power Supply Rejection Ratio (PSRR)
Positive PSRR
Negative PSRR
OPERATING TEMPERATURE RANGE
Test Conditions/Comments
R
L
= 1 kΩ to 1.5 V
R
L
= 150 Ω to 1.5 V
1% THD with 1 MHz, V
O
= 2 V p-p
Min
Typ
0.01 to 2.98
0.07 to 2.87
37
80
163
ADA4891-3 only
Part enabled
Part powered down
Part enabled, output rises to 90% of final value
Part powered down, output falls to 10% of final
value
2.7
ADA4891-3 only
+V
S
= 3 V to 3.15 V, −V
S
= 0 V
+V
S
= 3 V, −V
S
= −0.15 V to 0 V
−40
3.5
0.73
76
72
+125
1.3
48
−13
185
58
V
nA
μA
ns
ns
Max
Unit
V
V
mA
mA
mA
5.5
V
mA
mA
dB
dB
°C
Rev. B | Page 5 of
24
