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Wideband, Fast Settling Op Amp
AD840
FEATURES
CONNECTION DIAGRAMS
Wideband AC Performance
Gain Bandwidth Product: 400 MHz (Gain ≥ 10) Fast Settling: 100 ns to 0.01% for a 10 V Step
Plastic DIP (N) Package and
LCC (E) Package
Slew Rate: 400 V/s
Cerdip (Q) Package
Stable at Gains of 10 or Greater
Full Power Bandwidth: 6.4 MHz for 20 V p-p into a
500 ⍀ Load Precision DC Performance
Input Offset Voltage: 0.3 mV max Input Offset Drift: 3 V/؇C typ Input Voltage Noise: 4 nV/√Hz Open-Loop Gain: 130 V/mV into a 1 k⍀ Load Output Current: 50 mA min
OSupply Current: 12 mA max BAPPLICATIONS
Video and Pulse Amplifiers
SDAC and ADC Buffers OLine Drivers
Available in 14-Pin Plastic DIP, Hermetic Cerdip
Land 20-Pin LCC Packages and in Chip Form ETEMIL-STD-883B Processing Available
bandwidth active filters. The extremely rapid settling time of the AD840 makes it the preferred choice for data acquisition applications which require 12-bit accuracy. The AD840 is also appropriate for other applications such as high speed DAC and ADC buffer amplifiers and other wide bandwidth circuitry.
APPLICATION HIGHLIGHTS
1. The high slew rate and fast settling time of the AD840 make
PRODUCT DESCRIPTION The AD840 is a member of the Analog Devices’ family of wide bandwidth operational amplifiers. This high speed/high precision family includes, among others, the AD841, which is unitygain stable, and the AD842, which is stable at a gain of two or
it ideal for DAC and ADC buffers, line drivers and all types of video instrumentation circuitry.
2. The AD840 is truly a precision amplifier. It offers 12-bit accuracy to 0.01% or better and wide bandwidth, performance previously available only in hybrids.
greater and has 100 mA minimum output current drive. These
3. The AD840’s thermally balanced layout and the high speed
devices are fabricated using Analog Devices’ junction isolated
of the CB process allow the AD840 to settle to 0.01% in
complementary bipolar (CB) process. This process permits a
100 ns without the long “tails” that occur with other fast op
combination of dc precision and wideband ac performance
amps.
previously unobtainable in a monolithic op amp. In addition to its 400 MHz gain bandwidth product, the AD840 offers extremely fast settling characteristics, typically settling to within 0.01% of final value in 100 ns for a 10 volt step.
4. Laser wafer trimming reduces the input offset voltage to 0.3 mV max on the K grade, thus eliminating the need for external offset nulling in many applications. Offset null pins are provided for additional versatility.
The AD840 remains stable over its full operating temperature range at closed-loop gains of 10 or greater. It also offers a low quiescent current of 12 mA maximum, a minimum output current drive capability of 50 mA, a low input voltage noise of
5. Full differential inputs provide outstanding performance in all standard high frequency op amp applications where circuit gain will be 10 or greater.
4 nV/√Hz and a low input offset voltage of 0.3 mV maximum
6. The AD840 is an enhanced replacement for the HA2540.
(AD840K).
The 400 V/µs slew rate of the AD840, along with its 400 MHz gain bandwidth, ensures excellent performance in video and pulse amplifier applications. This amplifier is ideally suited for use in high frequency signal conditioning circuits and wide
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
AD840–SPECIFICATIONS (@ +25؇C and ؎15 V dc, unless otherwise noted)
Model
Conditions
AD840J Min Typ Max
AD840K Min Typ Max
AD840S Min Typ Max
Units
INPUT OFFSET VOLTAGE1 Offset Drift
TMIN–TMAX
0.2 1 1.5
5
0.1 0.3 0.7
3
0.2 1 2
5
mV mV µV/°C
INPUT BIAS CURRENT
TMIN–TMAX
3.5 8 10
3.5 5 6
3.5 8 12
µA µA
INPUT OFFSET CURRENT
TMIN–TMAX
0.1 0.4 0.5
0.1 0.2 0.3
0.1 0.4 0.6
µA µA
INPUT CHARACTERISTICS
Differential Mode
Input Resistance
30 30 30 kΩ
Input Capacitance
2 2 2 pF
INPUT VOLTAGE RANGE Common Mode Common-Mode Rejection
INPUT VOLTAGE NOISE
OWideband Noise BOPEN-LOOP GAIN SOLOUTPUT CHARACTERISTICS EVoltage TCurrent EOutput Resistance
VCM = ± 10 V TMIN–TMAX
f = 1 kHz 10 Hz to 10 MHz
VO = ± 10 V RLOAD = 1 kΩ TMIN–TMAX RLOAD = 500 Ω TMIN–TMAX
RLOAD ≥ 500 Ω TMIN–TMAX VOUT = ± 10 V Open Loop
؎10 12 90 110 85
4 10
100 130 50 80 75 50
؎10 50
15
؎10 12 106 115 90
4 10
100 130 75 100 100 75
؎10 50
15
± 10 12 90 110 85
4 10
100 130 50 80 75 50
؎10 50
15
V dB dB
nV/√Hz µV rms
V/mV V/mV V/mV V/mV
V mA Ω
FREQUENCY RESPONSE Gain Bandwidth Product
Full Power Bandwidth2
Rise Time Overshoot3 Slew Rate3 Settling Time3 – 10 V .