450 V/ꢀs, Precision,
Current-Feedback Op Amp
a
AD846
FEATURES
CONNECTION DIAGRAMS
AC PERFORMANCE
Small Signal Bandwidth: 80 MHz (AV = –1)
Slew Rate: 450 V/ꢀs
Plastic Mini-DIP (N) Package
and
Cerdip (Q) Package
Full Power Bandwidth: 6.8 MHz at 20 V p-p,
RL = 500 ꢁ
Fast Settling: for 10 V Step: 110 ns to 0.01%,
80 ns to 0.1%
Differential Gain: <0.01% @ 4.4 MHz
Differential Phase: <0.028ꢂ @ 4.4 MHz
Total Harmonic Distortion (THD): 0.0005% @ 100 kHz
Open-Loop Transimpedance: 200 Mꢁ
Input Voltage Noise: 2 nV/√Hz
DC PERFORMANCE
Input Offset Voltage: 75 ꢀV max (B Grade)
Input Offset Drift: 3.5 ꢀV/ꢂC max (B Grade)
Quiescent Supply Current: 6.5 mA max
SOIC (R) Package
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
NC
NC
NC
NC
+V
AD846
APPLICATIONS
High Speed DAC Buffers
Multiflash ADC Error Amplifiers
Flash ADC Buffers
Coaxial Cable Drivers
High Performance Audio Circuitry
Available in Plastic Mini-DIP, Hermetic Cerdip, and
Plastic SOIC (A) Package
–
+
–INPUT
NC
S
NC
+INPUT
NC
OUTPUT
COMPENSATION
TOP VIEW
(Not to Scale)
–V
S
NC
NC
NC
MIL-STD-883B Part Available
NC = NO CONNECT
PRODUCT DESCRIPTION
The AD846 is a monolithic, very high speed operational ampli-
fier offering high performance. Although technically classed as a
current-feedback or transimpedance amplifier, it may be used
in much the same way as traditional op amps while providing
significant performance benefits. Employing Analog Devices’
junction isolated complementary bipolar (CB) process, the AD846
achieves true “12-bit” (0.01%) precision on critical ac and dc
parameters, a level of performance unmatched by amplifiers
fabricated using either the dielectrically isolated (DI) or other
bipolar processes.
The AD846 is available in three performance grades. The AD846A
and AD846B are rated over the industrial temperature range
of –40°C to +85°C. The AD846S is rated over the full mili-
tary temperature range of –55°C to +125°C and is available
processed to MIL-STD-883B, Rev C.
The AD846 is available in two types of 8-lead packages: plastic
mini-DIP and hermetic cerdip. The AD846AR-16 is available in
the 16-lead SOIC package. “A” and “S” grade chips are also
available.
The AD846 offers significant advantages over conventional
high speed operational amplifiers. It maintains a nearly con-
stant bandwidth and settling time to 0.01% over a wide range
of closed-loop gains. This makes the AD846 ideal for amplifying
the residue in multiple-pass analog-to-digital converters.
PRODUCT HIGHLIGHTS
1. The AD846 achieves settling times of 110 ns to 0.01%
for gains of –1 to –10, with a 450 V/µs slew rate, while
consuming only 5 mA of supply current.
2. For closed-loop gains of –1 to –100, the high speed perfor-
mance of the AD846 is achieved without sacrificing full 12-bit
dc precision.
Other advantages include: low input errors and high open-loop
transresistance (200 MΩ) into a 500 Ω load, ensuring true
12-bit dc accuracy for closed-loop gains from –1 to gains
greater than –100. This combination of ac and dc perfor-
mance makes the AD846 an excellent choice for buffering
precision high speed DACs and flash ADCs.
3. The AD846 is well suited to line driver and video buffer
applications where the properties of low distortion and high
slew rate are required.
REV. C
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
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© Analog Devices, Inc., 2000