a
AD8079
FEATURES
Factory Set Gain
AD8079A: Gain = +2.0 (Also +1.0 & –1.0)
AD8079B: Gain = +2.2 (Also +1 & –1.2)
Gain of 2.2 Compensates for System Gain Loss
Minimizes External Components
Tight Control of Gain and Gain Matching (0.1%)
Optimum Dual Pinout
Simplifies PCB Layout
Low Crosstalk of –70 dB @ 5 MHz
Excellent Video Specifications (R
L
= 150 V)
Gain Flatness 0.1 dB to 50 MHz
0.01% Differential Gain Error
0.028 Differential Phase Error
Low Power of 50 mW/Amplifier (5 mA)
High Speed and Fast Settling
260 MHz, –3 dB Bandwidth
750 V/ms Slew Rate (2 V Step), 800 V/ms (4 V Step)
40 ns Settling Time to 0.1% (2 V Step)
Low Distortion of –65 dBc THD, f
C
= 5 MHz
High Output Drive of Over 70 mA
Drives Up to 8 Back-Terminated 75 V Loads (4 Loads/
Side) While Maintaining Good Differential Gain/
Phase Performance (0.01%/0.178)
High ESD Tolerance (5 kV)
Available in Small 8-Pin SOIC
APPLICATIONS
Differential A-to-D Driver
Video Line Driver
Differential Line Driver
Professional Cameras
Video Switchers
Special Effects
RF Receivers
FUNCTIONAL BLOCK DIAGRAM
8-Pin Plastic SOIC
1
2
3
4
5
6
7
8
AD8079
+IN1
GND
GND
+IN2
OUT1
+V
S
–V
S
OUT2
Dual 260 MHz
Gain = +2.0 & +2.2 Buffer
REV. A
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.
PRODUCT DESCRIPTION
The AD8079 is a dual, low power, high speed buffer designed
to operate on ±5 V supplies. The AD8079’s pinout offers excel-
lent input and output isolation compared to the traditional dual
amplifier pin configuration. With two ac ground pins separating
both the inputs and outputs, the AD8079 achieves very low
crosstalk of less than –70 dB at 5 MHz.
Additionally, the AD8079 contains gain setting resistors factory
set at G = +2.0 (A grade) or Gain = +2.2 (B grade) allowing
circuit configurations with minimal external components. The
B grade gain of +2.2 compensates for gain loss through a system
by providing a single-point trim. Using active laser trimming of
these resistors, the AD8079 guarantees tight control of gain and
channel-channel gain matching. With its performance and con-
figuration, the AD8079 is well suited for driving differential
cables and transformers. Its low distortion and fast settling are
ideal for buffering high speed dual or differential A-to-D con-
verters.
The AD8079 features a unique transimpedance linearization
circuitry. This allows it to drive video loads with excellent differ-
ential gain and phase performance of 0.01% and 0.02° on only
50 mW of power per amplifier. It features gain flatness of 0.1 dB
to 50 MHz. This makes the AD8079 ideal for professional video
electronics such as cameras and video switchers.
The AD8079 offers low power of 5 mA/amplifier (V
S
= ±5 V)
and can run on a single +12 V power supply while delivering
over 70 mA of load current. All of this is offered in a small 8-pin
SOIC package. These features make this amplifier ideal for por-
table and battery powered applications where size and power are
critical.
The outstanding bandwidth of 260 MHz along with 800 V/µs of
slew rate make the AD8079 useful in many general purpose high
speed applications where dual power supplies of ±3 V to ±6 V
are required.
The AD8079 is available in the industrial temperature range of
–40°C to +85°C.
FREQUENCY – Hz
1M
NORMALIZED FLATNESS – dB
1G10M 100M
–0.5
0.1
0
–0.1
–0.2
–0.3
–0.4
1
0
–9
–1
–2
–3
–4
–5
–6
–7
–8
NORMALIZED FREQUENCY RESPONSE – dB
SIDE 2
SIDE 1
SIDE 2
SIDE 1
R
L
= 100Ω
V
IN
= 50mV rms
50Ω
50Ω
Figure 1. Frequency Response and Flatness
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 World Wide Web Site: http://www.analog.com
Fax: 617/326-8703 © Analog Devices, Inc., 1996
