Low Distortion, High Speed
Rail-to-Rail Input/Output Amplifiers
AD8027/AD8028
FEATURES
High speed
190 MHz, –3 dB bandwidth (G = +1)
100 V/µs slew rate
Low distortion
120 dBc @ 1 MHz SFDR
80 dBc @ 5 MHz SFDR
Selectable input crossover threshold
Low noise
4.3 nV/√Hz
1.6 pA/√Hz
Low offset voltage: 900 µV max
Low power: 6.5 mA/amplifier supply current
Power-down mode
No phase reversal: V
IN
> |V
S
| + 200 mV
Wide supply range: 2.7 V to 12 V
Small packaging: SOIC-8, SOT-23-6, MSOP-10
SOIC-8
(R)
NC
1
–IN
2
+IN
3
–V
S 4
8
7
6
5
CONNECTION DIAGRAMS
SOT-23-6
(RT)
DISABLE/SELECT
+V
S
V
OUT
NC
+IN
3
MSOP-10
(RM)
8
4
V
OUT 1
–V
S 2
6
+V
S
DISABLE/SELECT
–IN
+
–
5
NC = NO CONNECT
SOIC-8
(R)
V
OUTA 1
–IN A
2
+IN A
3
–V
S 4
–
+
+
–
+V
S
V
OUTB
–IN B
+IN B
V
OUTA 1
–IN A
2
+IN A
3
–V
S 4
DISABLE/SELECT A
5
03327-B-001
10
+V
S
7
6
5
–
+
–
+
9
8
7
6
V
OUTB
–IN B
+IN B
DISABLE/SELECT B
Figure 1. Connection Diagrams (Top View)
APPLICATIONS
Filters
ADC drivers
Level shifting
Buffering
Professional video
Low voltage instrumentation
With its wide supply voltage range (2.7 V to 12 V) and wide
bandwidth (190 MHz), the AD8027/AD8028 amplifier is
designed to work in a variety of applications where speed and
performance are needed on low supply voltages. The high per-
formance of the AD8027/AD8028 is achieved with a quiescent
current of only 6.5 mA/amplifier typical. The AD8027/AD8028
has a shut down mode that is controlled via the SELECT pin.
The AD8027/AD8028 is available in SOIC-8, MSOP-10, and
SOT-23-6 packages. They are rated to work over the industrial
temperature range of –40°C to +125°C.
–20
G = +1
FREQUENCY = 100kHz
R
L
= 1kΩ
GENERAL DESCRIPTION
The AD8027/AD8028
1
is a high speed amplifier with rail-to-
rail input and output that operates on low supply voltages and
is optimized for high performance and wide dynamic signal
range. The AD8027/AD8028 has low noise (4.3 nV/√Hz,
1.6 pA/√Hz) and low distortion (120 dBc @ 1 MHz). In appli-
cations that use a fraction of or the entire input dynamic range
and require low distortion, the AD8027/AD8028 is an ideal
choice.
Many rail-to-rail input amplifiers have an input stage that
switches from one differential pair to another as the input sig-
nal crosses a threshold voltage, which causes distortion. The
AD8027/AD8028 has a unique feature that allows the user to
select the input crossover threshold voltage through the
SELECT pin. This feature controls the voltage at which the
complementary transistor input pairs switch. The AD8027/
AD8028 also has intrinsically low crossover distortion.
–40
–60
V
S
= +3V
SFDR (dB)
V
S
= +5V
V
S
=
±5V
–80
–100
–120
–140
0
1
2
3
4
5
6
7
OUTPUT VOLTAGE (V p-p)
8
9
10
03327-A-063
Figure 2. SFDR vs. Output Amplitude
1
Protected by U.S. patent numbers 6,486,737B1; 6,518,842B1
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.326.8703
© 2003 Analog Devices, Inc. All rights reserved.
AD8027/AD8028
TABLE OF CONTENTS
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 6
Maximum Power Dissipation ..................................................... 6
Typical Performance Characteristics ............................................. 7
Theory of Operation ...................................................................... 16
Input Stage................................................................................... 16
Crossover Selection .................................................................... 16
Output Stage................................................................................ 17
DC Errors .................................................................................... 17
Wideband Operation ..................................................................... 18
Circuit Considerations .............................................................. 19
Applications..................................................................................... 20
Using the AD8027/AD8028 SELECT Pin ............................... 20
Driving a 16-Bit ADC ................................................................ 20
Band-Pass Filter.......................................................................... 21
Design Tools and Technical Support ....................................... 21
Outline Dimensions ....................................................................... 22
Ordering Guide .......................................................................... 23
REVISION HISTORY
Revision B:
10/03—Data Sheet changed from Rev. A to Rev. B
Changes to Figure 1...........................................................................1
Revision A:
8/03—Data Sheet changed from Rev. 0 to Rev. A
Addition of AD8028........................................................... Universal
Changes to GENERAL DESCRIPTION.........................................1
Changes to Figures 1, 3, 4, 8, 13, 15, 17............................ 1, 6, 7, 8, 9
Changes to Figures 58, 60 .........................................................18, 20
Changes to SPECIFICATIONS........................................................3
Updated OUTLINE DIMENSIONS .............................................22
Updated ORDERING GUIDE.......................................................23
Revision 0: Initial Version
Rev. B | Page 2 of 24
AD8027/AD8028
SPECIFICATIONS
Table 1. V
S
= ±5 V (@ T
A
= 25°C, R
L
= 1 kΩ to midsupply, G = +1, unless otherwise noted.)
Parameter
DYNAMIC PERFORMANCE
–3 dB Bandwidth
Bandwidth for 0.1 dB Flatness
Slew Rate
Settling Time to 0.1%
NOISE/DISTORTION PERFORMANCE
Spurious Free Dynamic Range (SFDR)
Input Voltage Noise
Input Current Noise
Differential Gain Error
Differential Phase Error
Crosstalk, Output to Output
DC PERFORMANCE
Input Offset Voltage
Input Offset Voltage Drift
Input Bias Current
1
Input Bias Current
1
Input Offset Current
Open-Loop Gain
INPUT CHARACTERISTICS
Input Impedance
Input Capacitance
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
SELECT PIN
Crossover Low—Selection Input Voltage
Crossover High—Selection Input Voltage
Disable Input Voltage
Disable Switching Speed
Enable Switching Speed
OUTPUT CHARACTERISTICS
Output Overdrive Recovery Time
(Rising/Falling Edge)
Output Voltage Swing
Short Circuit Output
Off Isolation
Capacitive Load Drive
POWER SUPPLY
Operating Range
Quiescent Current/Amplifier
Quiescent Current (Disabled)
Power Supply Rejection Ratio
Conditions
G = +1, V
O
= 0.2 V p-p
G = +1, V
O
= 2 V p-p
G = +2, V
O
= 0.2 V p-p
G = +1, V
O
= 2 V Step/G = –1, V
O
= 2 V Step
G = +2, V
O
= 2 V Step
f
C
= 1 MHz, V
O
= 2 V p-p, R
F
= 24.9 Ω
f
C
= 5 MHz, V
O
= 2 V p-p, R
F
= 24.9 Ω
f = 100 kHz
f = 100 kHz
NTSC, G = +2, R
L
= 150 Ω
NTSC, G = +2, R
L
= 150 Ω
G = +1, R
L
=100 Ω, V
OUT
= 2 V p-p,
V
S
= ±5 V @ 1 MHz
SELECT = Tri-State or Open, PNP Active
SELECT = High NPN Active
T
MIN
to T
MAX
V
CM
= 0 V, NPN Active
T
MIN
to T
MAX
V
CM
= 0 V, PNP Active
T
MIN
to T
MAX
V
O
= ±2.5 V
100
Min
138
20
Typ
190
32
16
90/100
35
120
80
4.3
1.6
0.1
0.2
–93
Max
Unit
MHz
MHz
MHz
V/µs
ns
dBc
dBc
nV/√
Hz
pA/√
Hz
%
Degree
dB
200
240
1.50
4
4
–8
–8
±0.1
110
6
2
–5.2 to +5.2
110
–3.3 to +5
–3.9 to –3.3
–5 to –3.9
980
45
40/45
800
900
6
–11
±0.9
µV
µV
µV/°C
µA
µA
µA
µA
µA
dB
MΩ
pF
V
dB
V
V
V
ns
ns
ns
V
CM
= ±2.5 V
Tri-State < ±20 µA
90
50% of Input to <10% of Final V
O
V
I
= +6 V to –6 V, G = –1
–V
S
+ 0.10
Sinking and Sourcing
V
IN
= 0.2 V p-p, f = 1 MHz, SELECT = Low
30% Overshoot
2.7
SELECT = Low
V
S
± 1 V
+V
S
– 0.06,
–V
S
+ 0.06
120
–49
20
+V
S
– 0.10
V
mA
dB
pF
90
6.5
370
110
12
8.5
500
V
mA
µA
dB
1
No sign or a plus indicates current into pin, minus indicates current out of pin.
Rev. B | Page 3 of 24
AD8027/AD8028
SPECIFICATIONS
Table 2. V
S
= +5 V (@ T
A
= 25°C, R
L
= 1 kΩ to midsupply, unless otherwise noted.)
Parameter
DYNAMIC PERFORMANCE
–3 dB Bandwidth
Bandwidth for 0.1 dB Flatness
Slew Rate
Settling Time to 0.1%
NOISE/DISTORTION PERFORMANCE
Spurious Free Dynamic Range (SFDR)
Input Voltage Noise
Input Current Noise
Differential Gain Error
Differential Phase Error
Crosstalk, Output to Output
DC PERFORMANCE
Input Offset Voltage
Input Offset Voltage Drift
Input Bias Current
1
Input Bias Current
1
Input Offset Current
Open-Loop Gain
INPUT CHARACTERISTICS
Input Impedance
Input Capacitance
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
SELECT PIN
Crossover Low—Selection Input Voltage
Crossover High—Selection Input Voltage
Disable Input Voltage
DISABLE Switching Speed
Enable Switching Speed
OUTPUT CHARACTERISTICS
Overdrive Recovery Time
(Rising/Falling Edge)
Output Voltage Swing
Off Isolation
Short Circuit Current
Capacitive Load Drive
POWER SUPPLY
Operating Range
Quiescent Current/Amplifier
Quiescent Current (Disabled)
Power Supply Rejection Ratio
Conditions
G = +1, V
O
= 0.2 V p-p
G = +1, V
O
= 2 V p-p
G = +2, V
O
= 0.2 V p-p
G = +1, V
O
= 2 V Step/G = –1, V
O
= 2 V Step
G = +2, V
O
= 2 V Step
f
C
= 1 MHz, V
O
= 2 V p-p, R
F
= 24.9 Ω
f
C
= 5 MHz, V
O
= 2 V p-p, R
F
= 24.9 Ω
f = 100 kHz
f = 100 kHz
NTSC, G = +2, R
L
= 150 Ω
NTSC, G = +2, R
L
= 150 Ω
G = 1, R
L
= 100 Ω, V
OUT
= 2 V p-p,
V
S
= ±5 V @ 1 MHz
SELECT = Tri-State or Open, PNP Active
SELECT = High NPN Active
T
MIN
to T
MAX
V
CM
= 2.5 V, NPN Active
T
MIN
to T
MAX
V
CM
= 2.5 V, PNP Active
T
MIN
to T
MAX
V
O
= 1 V to 4 V
96
Min
131
18
Typ
185
28
12
85/100
40
90
64
4.3
1.6
0.1
0.2
–92
Max
Unit
MHz
MHz
MHz
V/µs
ns
dBc
dBc
nV/√
Hz
pA/√
Hz
%
Degree
dB
200
240
2
4
4
–8
–8
±0.1
105
6
2
–0.2 to +5.2
105
1.7 to 5
1.1 to 1.7
0 to 1.1
1100
50
50/50
800
900
6
–11
±0.9
µV
µV
µV/°C
µA
µA
µA
µA
µA
dB
MΩ
pF
V
dB
V
V
V
ns
ns
ns
V
CM
= 0 V to 2.5 V
Tri-State < ±20 µA
90
50% of Input to <10% of Final V
O
V
I
= –1 V to +6 V, G = –1
R
L
= 1 kΩ
V
IN
= 0.2 V p-p, f = 1 MHz, SELECT = Low
Sinking and Sourcing
30% Overshoot
2.7
SELECT = Low
V
S
± 1 V
–V
S
+ 0.08
+V
S
– 0.04,
–V
S
+ 0.04
–49
105
20
+V
S
– 0.08
V
dB
mA
pF
90
6
320
105
12
8.5
450
V
mA
µA
dB
1
No sign or a plus indicates current into pin, minus indicates current out of pin.
Rev. B | Page 4 of 24
AD8027/AD8028
SPECIFICATIONS
Table 3. V
S
= +3 V (@ T
A
= 25°C, R
L
= 1 kΩ to midsupply, unless otherwise noted.)
Parameter
DYNAMIC PERFORMANCE
–3 dB Bandwidth
Bandwidth for 0.1 dB Flatness
Slew Rate
Settling Time to 0.1%
NOISE/DISTORTION PERFORMANCE
Spurious Free Dynamic Range (SFDR)
Input Voltage Noise
Input Current Noise
Differential Gain Error
Differential Phase Error
Crosstalk, Output to Output
DC PERFORMANCE
Input Offset Voltage
Input Offset Voltage Drift
Input Bias Current
1
Input Bias Current
1
Input Offset Current
Open-Loop Gain
INPUT CHARACTERISTICS
Input Impedance
Input Capacitance
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
SELECT PIN
Crossover Low—Selection Input Voltage
Crossover High—Selection Input Voltage
Disable Input Voltage
DISABLE Switching Speed
Enable Switching Speed
OUTPUT CHARACTERISTICS
Output Overdrive Recovery Time
(Rising/Falling Edge)
Output Voltage Swing
Short Circuit Current
Off Isolation
Capacitive Load Drive
POWER SUPPLY
Operating Range
Quiescent Current/Amplifier
Quiescent Current (Disabled)
Power Supply Rejection Ratio
Conditions
G = +1, V
O
= 0.2 V p-p
G = +1, V
O
= 2 V p-p
G = +2, V
O
= 0.2 V p-p
G = +1, V
O
= 2 V Step/G = –1, V
O
= 2 V Step
G = +2, V
O
= 2 V Step
f
C
= 1 MHz, V
O
= 2 V p-p, R
F
= 24.9
Ω
f
C
= 5 MHz, V
O
= 2 V p-p, R
F
= 24.9
Ω
f = 100 kHz
f = 100 kHz
NTSC, G = +2, R
L
= 150 Ω
NTSC, G = +2, R
L
= 150 Ω
G = 1, R
L
= 100 Ω, V
OUT
= 2 V p-p,
V
S
= 3 V @ 1 MHz
SELECT = Tri-State or Open, PNP Active
SELECT = High NPN Active
T
MIN
to T
MAX
V
CM
= 1.5 V, NPN Active
T
MIN
to T
MAX
V
CM
= 1.5 V, PNP Active
T
MIN
to T
MAX
V
O
= 1 V to 2 V
90
Min
125
19
Typ
180
29
10
73/100
48
85
64
4.3
1.6
0.15
0.20
–89
Max
Unit
MHz
MHz
MHz
V/µs
ns
dBc
dBc
nV/√
Hz
pA/√
Hz
%
Degree
dB
200
240
2
4
4
–8
–8
±0.1
100
6
2
–0.2 to +3.2
100
1.7 to 3
1.1 to 1.7
0 to 1.1
1150
50
55/55
800
900
6
–11
±0.9
µV
µV
µV/°C
µA
µA
µA
µA
µA
dB
MΩ
pF
V
dB
V
V
V
ns
ns
ns
R
L
= 1 kΩ
V
CM
= 0 V to 1.5 V
Tri-State < ±20 µA
88
50% of Input to <10% of Final V
O
V
I
= –1 V to +4 V, G = –1
R
L
= 1 kΩ
Sinking and Sourcing
V
IN
= 0.2 V p-p, f = 1 MHz, SELECT = Low
30% Overshoot
2.7
SELECT = Low
V
S
± 1 V
–V
S
+ 0.07
+V
S
– 0.03,
–V
S
+ 0.03
72
–49
20
+V
S
– 0.07
V
mA
dB
pF
88
6.0
300
100
12
8.0
420
V
mA
µA
dB
1
No sign or a plus indicates current into pin, minus indicates current out of pin.
Rev. B | Page 5 of 24
