CONNECTION DIAGRAMS
16-Pin SOIC (R-16) Package Plastic (N-8) and
Cerdip (Q-8) Package
TO-8 (H-12A) Package LCC (E-20A) Package
REV. D
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which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
34 MHz, CBFET
Fast Settling Op Amp
AD843
© Analog Devices, Inc., 1995
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
PRODUCT DESCRIPTION
The AD843 is a fast settling, 34 MHz, CBFET input op amp.
The AD843 combines the low (0.6 nA) input bias currents
characteristic of a FET input amplifier while still providing a
34 MHz bandwidth and a 135 ns settling time (to within 0.01%
of final value for a 10 volt step). The AD843 is a member of the
Analog Devices’ family of wide bandwidth operational amplifi-
ers. These devices are fabricated using Analog Devices’ junction
isolated complementary bipolar (CB) process. This process per-
mits a combination of dc precision and wideband ac perform-
ance previously unobtainable in a monolithic op amp.
The 250 V/µs slew rate and 0.6 nA input bias current of the
AD843 ensure excellent performance in high speed sample-and-
hold applications and in high speed integrators. This amplifier is
also ideally suited for high bandwidth active filters and high fre-
quency signal conditioning circuits.
Unlike many high frequency amplifiers, the AD843 requires no
external compensation and it remains stable over its full operat-
ing temperature range. It is available in five performance grades:
the AD843J and AD843K are rated over the commercial
temperature range of 0°C to +70°C. The AD843A and AD843B
are rated over the industrial temperature range of –40°C to +85°C.
The AD843S is rated over the military temperature range of –55°C
to +125°C and is available processed to MIL-STD-883B, Rev. C.
FEATURES
AC PERFORMANCE
Unity Gain Bandwidth: 34 MHz
Fast Settling: 135 ns to 0.01%
Slew Rate: 250 V/ms
Stable at Gains of 1 or Greater
Full Power Bandwidth: 3.9 MHz
DC PERFORMANCE
Input Offset Voltage: 1 mV max (AD843K/B}
Input Bias Current: 0.6 nA typ
Input Voltage Noise: 19 nV/√
Hz
Open Loop Gain: 30 V/mV into a 500 V Load
Output Current: 50 mA min
Supply Current: 13 mA max
Available in 8-Pin Plastic Mini-DIP & Cerdip, 16-Pin SOIC,
20-Pin LCC and 12-Pin Hermetic Metal Can Packages
Available in Tape and Reel in Accordance with
EIA-481A Standard
Chips and MIL-STD-883B Parts Also Available
APPLICATIONS
High Speed Sample-and-Hold Amplifiers
High Bandwidth Active Filters
High Speed Integrators
High Frequency Signal Conditioning
The AD843 is offered in either 8-pin plastic DIP or hermetic
cerdip packages, in 16-pin SOIC, 20-Pin LCC, or in a 12-pin
metal can. Chips are also available.
PRODUCT HIGHLIGHTS
1. The high slew rate, fast settling time and low input bias cur-
rent of the AD843 make it the ideal amplifier for 12-bit D/A
and A/D buffers, for high speed sample-and-hold amplifiers
and for high speed integrator circuits. The AD843 can re-
place many FET input hybrid amplifiers such as the
LH0032, LH4104 and OPA600.
2. Fully differential inputs provide outstanding performance in
all standard high frequency op amp applications such as sig-
nal conditioning and active filters.
3. Laser wafer trimming reduces the input offset voltage to
1 mV max (AD843K and AD843B).
4. Although external offset nulling is unnecessary in many ap-
plications, offset null pins are provided.
5. The AD843 does not require external compensation at
closed loop gains of 1 or greater.
