High-Speed, Low-Noise
Video Op Amp
a
AD829
CONNECTION DIAGRAMS
FEATURES
High Speed
120 MHz Bandwidth, Gain = –1
230 V/s Slew Rate
8-Lead Plastic Mini-DIP (N),
Cerdip (Q) and SOIC (R) Packages
90 ns Settling Time to 0.1%
Ideal for Video Applications
0.02% Differential Gain
0.04؇ Differential Phase
Low Noise
1
2
3
4
8
7
6
5
OFFSET NULL
OFFSET NULL
AD829
+V
S
–IN
+IN
OUTPUT
TOP VIEW
(Not to Scale)
C
–V
S
COMP
1.7 nV/√Hz Input Voltage Noise
1.5 pA/√Hz Input Current Noise
Excellent DC Precision
20-Lead LCC Pinout
1 mV max Input Offset Voltage (Over Temp)
0.3 V/؇C Input Offset Drift
Flexible Operation
Specified for ؎5 V to ؎15 V Operation
؎3 V Output Swing into a 150 ⍀ Load
External Compensation for Gains 1 to 20
5 mA Supply Current
3
2
1 20 19
18 NC
+V
4
5
6
7
8
NC
–IN
NC
+IN
NC
17
16 NC
AD829
TOP VIEW
Available in Tape and Reel in Accordance with
EIA-481A Standard
(Not to Scale)
OUTPUT
15
14 NC
PRODUCT DESCRIPTION
9
10 11 12 13
The AD829 is a low noise (1.7 nV/√Hz), high speed op amp
with custom compensation that provides the user with gains
from 1 to 20 while maintaining a bandwidth greater than
50 MHz. The AD829’s 0.04° differential phase and 0.02%
differential gain performance at 3.58 MHz and 4.43 MHz,
driving reverse-terminated 50 Ω or 75 Ω cables, makes it ideally
suited for professional video applications. The AD829 achieves
its 230 V/µs uncompensated slew rate and 750 MHz gain band-
width product while requiring only 5 mA of current from the
power supplies.
NC = NO CONNECT
The AD829 provides many of the same advantages that a trans-
impedance amplifier offers, while operating as a traditional
voltage feedback amplifier. A bandwidth greater than 50 MHz
can be maintained for a range of gains by changing the external
compensation capacitor. The AD829 and the transimpedance
amplifier are both unity gain stable and provide similar voltage
noise performance (1.7 nV/√Hz). However, the current noise of
the AD829 (1.5 pA/√Hz) is less than 10% of the noise of trans-
impedance amps. Furthermore, the inputs of the AD829 are
symmetrical.
The AD829’s external compensation pin gives it exceptional
versatility. For example, compensation can be selected to opti-
mize the bandwidth for a given load and power supply voltage.
As a gain-of-two line driver, the –3 dB bandwidth can be in-
creased to 95 MHz at the expense of 1 dB of peaking. In addi-
tion, the AD829’s output can also be clamped at its external
compensation pin.
PRODUCT HIGHLIGHTS
1. Input voltage noise of 2 nV/√Hz, current noise of 1.5 pA/
√Hz and 50 MHz bandwidth, for gains of 1 to 20, make the
AD829 an ideal preamp.
2. Differential phase error of 0.04° and a 0.02% differential
gain error, at the 3.58 MHz NTSC and 4.43 MHz PAL and
SECAM color subcarrier frequencies, make it an outstanding
video performer for driving reverse-terminated 50 Ω and
75 Ω cables to 1 V (at their terminated end).
3. The AD829 can drive heavy capacitive loads.
4. Performance is fully specified for operation from 5 V to
15 V supplies.
5. Available in plastic, cerdip, and small outline packages.
Chips and MIL-STD-883B parts are also available.
The AD829 has excellent dc performance. It offers a minimum
open-loop gain of 30 V/mV into loads as low as 500 Ω, low
input voltage noise of 1.7 nV/√Hz, and a low input offset volt-
age of 1 mV maximum. Common-mode rejection and power
supply rejection ratios are both 120 dB.
The AD829 is also useful in multichannel, high speed data
conversion where its fast (90 ns to 0.1%) settling time is of
importance. In such applications, the AD829 serves as an input
buffer for 8-to-10-bit A/D converters and as an output I/V con-
verter for high speed D/A converters.
REV. E
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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Tel: 781/329-4700
Fax: 781/326-8703
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© Analog Devices, Inc., 2000