Low Cost, 300 MHz
Voltage Feedback Amplifiers
a
AD8055/AD8056
FUNCTIONAL BLOCK DIAGRAMS
FEATURES
Low Cost Single (AD8055) and Dual (AD8056)
Easy to Use Voltage Feedback Architecture
High Speed
300 MHz, –3 dB Bandwidth (G = +1)
1400 V/s Slew Rate
20 ns Settling to 0.1%
Low Distortion: –72 dBc @ 10 MHz
Low Noise: 6 nV/√Hz
N-8 and SO-8
SOT-23-5 (RT)
AD8055
AD8055
1
2
3
4
NC
+V
+V
S
8
7
6
5
V
1
2
5
4
NC
–IN
+IN
OUT
S
–V
S
V
OUT
NC
–V
3
–IN
+IN
S
(Not to Scale)
(Not to Scale)
NC = NO CONNECT
Low DC Errors: 5 mV Max VOS, 1.2 A Max IB
Small Packaging
N-8, SO-8, microSOIC (RM)
AD8055 Available in SOT-23-5
AD8056 Available in 8-Lead microSOIC
Excellent Video Specifications (RL = 150 ⍀, G = +2)
Gain Flatness 0.1 dB to 40 MHz
0.01% Differential Gain Error
AD8056
1
2
3
4
+V
S
OUT1
–IN1
+IN1
8
7
6
5
OUT
–IN2
+IN2
–V
S
0.02؇ Differential Phase Error
(Not to Scale)
Drives Four Video Loads (37.5 ⍀) with 0.02% and
0.1؇ Differential Gain and Differential Phase
Low Power, ؎5 V Supplies
5 mA Typ/Amplifier Power Supply Current
High Output Drive Current: Over 60 mA
The AD8055 and AD8056 require only 5 mA typ/amplifier of
supply current and operate on dual 5 V or single +12 V power
supply, while being capable of delivering over 60 mA of load
current. All this is offered in a small 8-lead plastic DIP, 8-lead
SOIC packages, 5-lead SOT-23-5 package (AD8055) and an
8-lead microSOIC package (AD8056). These features make
the AD8055/AD8056 ideal for portable and battery powered
applications where size and power are critical. These amplifiers are
available in the industrial temperature range of –40°C to +85°C.
APPLICATIONS
Imaging
Photodiode Preamp
Video Line Driver
Differential Line Driver
Professional Cameras
Video Switchers
Special Effects
5
V
R
= 100mV p-p
= 100⍀
R
C
OUT
4
3
V
IN
V
A-to-D Driver
Active Filters
OUT
L
50⍀
G = +1
R
L
R
R
= 0⍀
= 100⍀
F
R
F
2
R
S
C
G = +2
= 402⍀
1
R
PRODUCT DESCRIPTION
F
0
The AD8055 (single) and AD8056 (dual) voltage feedback
amplifiers offer bandwidth and slew rate typically found in cur-
rent feedback amplifiers. Additionally, these amplifiers are easy
to use and available at a very low cost.
–1
–2
–3
–4
G = +10
R
= 909⍀
F
Despite their low cost, the AD8055 and AD8056 provide excel-
lent overall performance. For video applications, their differen-
tial gain and phase error are 0.01% and 0.02° into a 150 Ω load,
and 0.02% and 0.1° while driving four video loads (37.5 Ω).
Their 0.1 dB flatness out to 40 MHz, wide bandwidth out to
300 MHz, along with 1400 V/µs slew rate and 20 ns settling
time, make them useful for a variety of high speed applications.
G = +5
R
= 1000⍀
F
–5
0.3M
1M
10M
100M
1G
FREQUENCY – Hz
Figure 1. Frequency Response
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
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© Analog Devices, Inc., 2000