Ultralow Noise
BiFET Op Amp
a
AD743
CO NNECTIO N D IAGRAMS
8-P in P lastic Mini-D IP (N)
FEATURES
ULTRALOW NOISE PERFORMANCE
2.9 nV/ √Hz at 10 kHz
0.38 V p-p, 0.1 Hz to 10 Hz
6.9 fA/ √Hz Current Noise at 1 kHz
and
16-P in SO IC (R) P ackage
8-P in Cer dip (Q ) P ackages
1
2
3
4
5
6
8
NC
1
2
3
4
8
16 NC
NULL
–IN
NC
+V
AD743
EXCELLENT DC PERFORMANCE
0.5 m V m ax Offset Voltage
250 pA m ax Input Bias Current
1000 V/ m V m in Open-Loop Gain
OFFSET
NULL
15
NC
7
6
5
S
AD743
–IN
NC
+IN
NC
+V
14
13
+IN
OUT
–V
S
NULL
S
TOP VIEW
AC PERFORMANCE
2.8 V/ s Slew Rate
4.5 MHz Unity-Gain Bandw idth
THD = 0.0003% @ 1 kHz
Available in Tape and Reel in Accordance w ith
EIA-481A Standard
12 OUTPUT
NC = NO CONNECT
OFFSET
11
–V
S
NULL
NC
NC
7
8
10
9
NC
NC
NC = NO CONNECT
APPLICATIONS
P RO D UCT H IGH LIGH TS
Sonar Pream plifiers
1. T he low offset voltage and low input offset voltage drift of
the AD743 coupled with its ultralow noise performance
mean that the AD743 can be used for upgrading many
applications now using bipolar amplifiers.
High Dynam ic Range Filters (>140 dB)
Photodiode and IR Detector Am plifiers
Accelerom eters
2. T he combination of low voltage and low current noise make
the AD743 ideal for charge sensitive applications such as
accelerometers and hydrophones.
P RO D UCT D ESCRIP TIO N
T he AD743 is an ultralow noise precision, FET input,
monolithic operational amplifier. It offers a combination of the
ultralow voltage noise generally associated with bipolar input op
amps and the very low input current of a FET -input device.
Furthermore, the AD743 does not exhibit an output phase
reversal when the negative common-mode voltage limit is
exceeded.
3. T he low input offset voltage and low noise level of the
AD743 provide >140 dB dynamic range.
4. T he typical 10 kHz noise level of 2.9 nV/√Hz permits a three
op amp instrumentation amplifier, using three AD743s, to be
built which exhibits less than 4.2 nV/√Hz noise at 10 kHz
and which has low input bias currents.
T he AD743’s guaranteed, maximum input voltage noise of
4.0 nV/√Hz at 10 kHz is unsurpassed for a FET -input
monolithic op amp, as is the maximum 1.0 µV p-p, 0.1 Hz to
10 Hz noise. T he AD743 also has excellent dc performance with
250 pA maximum input bias current and 0.5 mV maximum
offset voltage.
1000
OP27 &
RESISTOR
R
SOURCE
( — )
E
O
R
100
SOURCE
T he AD743 is specifically designed for use as a preamp in
capacitive sensors, such as ceramic hydrophones. It is available
in five performance grades. T he AD743J and AD743K are rated
over the commercial temperature range of 0°C to +70°C. T he
AD743A and AD743B are rated over the industrial temperature
range of –40°C to +85°C. T he AD743S is rated over the
military temperature range of –55°C to +125°C and is available
processed to MIL-ST D-883B, Rev. C.
AD743 + RESISTOR
AD743 & RESISTOR
OR
OP27 & RESISTOR
)
(
10
RESISTOR NOISE ONLY
(– – –)
T he AD743 is available in 8-pin plastic mini-DIP, 8-pin cerdip,
16-pin SOIC, or in chip form.
1
100
10M
1M
10k
100k
1k
SOURCE RESISTANCE – Ω
Input Noise Voltage vs. Source Resistance
REV. C
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norw ood, MA 02062-9106, U.S.A.
Tel: 617/ 329-4700
Fax: 617/ 326-8703