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: VIN > |VS| + 200 mV
Wide supply range: 2.7 V to 12 V
Small packaging: SOIC-8, SOT-23-6, MSOP-10
APPLICATIONS
Filters
ADC drivers
Level shifting
Buffering
Professional video
Low voltage instrumentation
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.
CONNECTION DIAGRAMS
SOT-23-6
(RT)
V
OUT
1
–V
S
2
+IN 3
5
6 +V
S
DISABLE/SELECT
4 –IN
+–
03327-B-001
NC = NO CONNECT
NC
SOIC-8
(R)
1
–IN 2
+IN 3
–V
S
4
+V
S
V
OUT
NC
8
7
6
5
DISABLE/SELECT
V
OUTB
–IN B
+IN B
8
7
6
5
+V
S
V
OUTA
SOIC-8
(R)
1
–IN A 2
+IN A 3
–V
S
4
+
–
+
–
V
OUTB
10
9
+V
S
DISABLE/SELECT B
–IN B
+IN B
8
7
6DISABLE/SELECT A
V
OUTA
MSOP-10
(RM)
1
–IN A 2
+IN A 3
–V
S
4
5
+
–
+
–

Figure 1. Connection Diagrams (Top View)
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.
OUTPUT VOLTAGE (V p-p)
012345678910
–140
–120
–100
–80
–60
–40
–20
SF
DR (d
B)
G = +1
FREQUENCY = 100kHz
R
L
= 1kΩ
V
S
= ±5V
V
S
= +3V
V
S
= +5V
03327-A-063

Figure 2. SFDR vs. Output Amplitude


1
Protected by U.S. patent numbers 6,486,737B1; 6,518,842B1
Rev. B
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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
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