a
FEATURES
Wideband AC Performance
Gain Bandwidth Product: 400 MHz (Gain
≥
10)
Fast Settling: 100 ns to 0.01% for a 10 V Step
Slew Rate: 400 V/ s
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
Supply Current: 12 mA max
APPLICATIONS
Video and Pulse Amplifiers
DAC and ADC Buffers
Line Drivers
Available in 14-Pin Plastic DIP, Hermetic Cerdip
and 20-Pin LCC Packages and in Chip Form
MIL-STD-883B Processing Available
Wideband,
Fast Settling Op Amp
AD840
CONNECTION DIAGRAMS
Plastic DIP (N) Package
and
Cerdip (Q) Package
LCC (E) Package
bandwidth active filters. The extremely rapid settling time of the
AD840 makes it the preferred choice for data acquisition appli-
cations which require 12-bit accuracy. The AD840 is also ap-
propriate for other applications such as high speed DAC and
ADC buffer amplifiers and other wide bandwidth circuitry.
APPLICATION HIGHLIGHTS
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 unity-
gain stable, and the AD842, which is stable at a gain of two or
greater and has 100 mA minimum output current drive. These
devices are fabricated using Analog Devices’ junction isolated
complementary bipolar (CB) process. This process permits a
combination of dc precision and wideband ac performance
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.
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
4 nV/√Hz and a low input offset voltage of 0.3 mV maximum
(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.
1. The high slew rate and fast settling time of the AD840 make
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, perfor-
mance previously available only in hybrids.
3. The AD840’s thermally balanced layout and the high speed
of the CB process allow the AD840 to settle to 0.01% in
100 ns without the long “tails” that occur with other fast op
amps.
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.
5. Full differential inputs provide outstanding performance
in all standard high frequency op amp applications where
circuit gain will be 10 or greater.
6. The AD840 is an enhanced replacement for the HA2540.
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
Model
Conditions
INPUT OFFSET VOLTAGE
1
T
MIN
–T
MAX
Offset Drift
INPUT BIAS CURRENT
T
MIN
–T
MAX
INPUT OFFSET CURRENT
T
MIN
–T
MAX
INPUT CHARACTERISTICS
Input Resistance
Input Capacitance
INPUT VOLTAGE RANGE
Common Mode
Common-Mode Rejection
Differential Mode
30
2
10
90
85
5
Min
15 V dc, unless otherwise noted)
Max
1
1.5
8
10
0.4
0.5
AD840K
Min
Typ
0.1
3
3.5
5
6
0.2
0.3
Max
0.3
0.7
AD840S
Min
Typ
Max
0.2
5
3.5
8
12
0.4
0.6
1
2
Units
mV
mV
µV/°C
µA
µA
µA
µA
kΩ
pF
V
dB
dB
nV/√Hz
µV
rms
V/mV
V/mV
V/mV
V/mV
AD840J
Typ
0.2
3.5
0.1
0.1
0.1
30
2
10
106
90
12
115
±
10
90
85
30
2
12
110
V
CM
=
±
10 V
T
MIN
–T
MAX
f = 1 kHz
10 Hz to 10 MHz
V
O
=
±
10 V
R
LOAD
= 1 kΩ
T
MIN
–T
MAX
R
LOAD
= 500
Ω
T
MIN
–T
MAX
R
LOAD
≥
500
Ω
T
MIN
–T
MAX
V
OUT
=
±
10 V
Open Loop
12
110
INPUT VOLTAGE NOISE
Wideband Noise
OPEN-LOOP GAIN
4
10
4
10
4
10
100
50
75
50
130
80
100
75
100
75
130
100
100
50
75
50
130
80
OUTPUT CHARACTERISTICS
Voltage
Current
Output Resistance
FREQUENCY RESPONSE
Gain Bandwidth Product
Full Power Bandwidth
2
10
50
15
10
50
15
10
50
15
V
mA
Ω
Rise Time
Overshoot
3
Slew Rate
3
Settling Time
3
– 10 V Step
V
OUT
= 90 mV p-p
A
V
= –10
V
O
= 20 V p-p
R
LOAD
= 500
Ω
A
V
= –10
A
V
= –10
A
V
= –10
A
V
= –10
to 0.1%
to 0.01%
–Overdrive
+Overdrive
f = 4.4 MHz
f = 4.4 MHz
400
5.5
6.4
10
20
400
80
100
190
350
0.025
0.04
±
15
5
12
18
14
16
5
5.5
400
6.4
10
20
400
80
100
190
350
0.025
0.04
±
15
12
94
86
+75
0
72
100
18
14
16
5
5.5
400
6.4
10
20
400
80
100
190
350
0.025
0.04
±
15
12
90
80
+75
–55
72
100
18
14
18
MHz
MHz
ns
%
V/µs
ns
ns
ns
ns
%
Degree
350
350
350
OVERDRIVE RECOVERY
DIFFERENTIAL GAIN
DIFFERENTIAL PHASE
POWER SUPPLY
Rated Performance
Operating Range
Quiescent Current
Power Supply Rejection Ratio
TEMPERATURE RANGE
Rated Performance
4
TRANSISTOR COUNT
T
MIN
–T
MAX
V
S
=
±
5 V to
±
18 V
T
MIN
–T
MAX
90
80
0
100
V
V
mA
mA
dB
dB
°C
+125
# of Transistors
72
–2–
REV. C
AD840
NOTES
1
Input offset voltage specifications are guaranteed after 5 minutes at T
A
= +25°C.
2
Full power bandwidth = slew rate/2
π
V
PEAK
.
3
Refer to Figures 22 and 23.
4
“S” grade T
MIN
–T
MAX
specifications are tested with automatic test equipment at T
A
= –55°C and T
A
= +125°C.
All min and max specifications are guaranteed. Specifications shown in
boldface
are tested on all production units.
Specifications subject to change without notice.
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
18 V
Internal Power Dissipation
2
Plastic (N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 W
Cerdip (Q) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 W
LCC (E) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 W
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
V
S
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . .
±
6 V
Storage Temperature Range
Q, E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .–65°C to +150°C
N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .–65°C to +125°C
Junction Temperature (T
J
) . . . . . . . . . . . . . . . . . . . . . +175°C
Lead Temperature Range (Soldering 60 sec) . . . . . . . . +300°C
NOTES
1
Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. This is a stress rating only, and functional
operation of the device at these or any other conditions above those indicated in
the operational section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
2
Maximum internal power dissipation is specified so that T
J
does not exceed
+175°C at an ambient temperature of +25°C.
Thermal Characteristics:
θ
JC
θ
JA
Derate at
Cerdip Package
30°C/W
110°C/W
8.7 mW/°C
Plastic Package
30°C/W
100°C/T
10 mW/°C
LCC Package
35°C/W
150°C/W
6.7 mW/°C
ABSOLUTE MAXIMUM RATINGS
1
Plastic DIP (N) Package
and
Cerdip (Q) Package
LCC (E) Package
Recommended Heat Sink:
Aavid Engineering© #602B
ORDERING GUIDE
Models
Package Options
2
AD840JN
AD840KN
AD840JQ
AD840KQ
AD840SQ
AD840SQ-883B
5962-89640012A
AD840SE-883B
5962-8964001CA
1
N-14
N-14
Q-14
Q-14
Q-14
Q-14
Q-14
E-20A
E-20A
AD840 Connection Diagrams
METALIZATION PHOTOGRAPH
Contact factory for latest dimensions.
Dimensions shown in inches and (mm).
NOTES
J and S Grade Chips also available.
2
N = Plastic DIP; Q = Cerdip; E = LCC (Leadless
2
Ceramic Chip Carrier).
REV. C
–3–
AD840–Typical Characteristics
(at +25 C and V
S
=
15 V, unless otherwise noted)
Figure 1. Input Common-Mode
Range vs. Supply Voltage
Figure 2. Output Voltage Swing
vs. Supply Voltage
Figure 3. Output Voltage Swing
vs. Load Resistance
Figure 4. Quiescent Current vs.
Supply Voltage
Figure 5. Input Bias Current vs.
Temperature
Figure 6. Output Impedance vs.
Frequency
Figure 7. Quiescent Current vs.
Temperature
Figure 8. Short-Circuit Current
Limit vs. Temperature
Figure 9. Gain Bandwidth Product
vs. Temperature
–4–
REV. C
AD840
Figure 10. Open-Loop Gain and
Phase Margin Phase vs. Frequency
Figure 11. Open-Loop Gain vs.
Supply Voltage
Figure 12. Power Supply Rejection
vs. Frequency
Figure 13. Common-Mode
Rejection vs. Frequency
Figure 14. Large Signal Frequency
Response
Figure 15. Output Swing and
Error vs. Settling Time
Figure 16. Harmonic Distortion vs.
Frequency
Figure 17. Input Voltage Noise
Spectral Density
Figure 18. Slew Rate vs.
Temperature
REV. C
–5–
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