Ultralow Noise,
High Speed, BiFET Op Amp
a
AD745
FEATURES
ULTRALOW NOISE PERFORMANCE
2.9 nV/ͱHz at 10 kHz
CONNECTION DIAGRAM
16-Lead SOIC (R) Package
0.38 ꢀV p-p, 0.1 Hz to 10 Hz
6.9 fA/ͱHz Current Noise at 1 kHz
EXCELLENT AC PERFORMANCE
12.5 V/ꢀs Slew Rate
20 MHz Gain Bandwidth Product
THD = 0.0002% @ 1 kHz
Internally Compensated for Gains of +5 (or –4) or
Greater
EXCELLENT DC PERFORMANCE
0.5 mV Max Offset Voltage
250 pA Max Input Bias Current
2000 V/mV Min Open Loop Gain
Available in Tape and Reel in Accordance with
EIA-481A Standard
APPLICATIONS
Sonar
Photodiode and IR Detector Amplifiers
Accelerometers
amplifier for high-speed applications demanding low noise and
high dc precision. Furthermore, the AD745 does not exhibit an
output phase reversal.
The AD745 also has excellent dc performance with 250 pA
maximum input bias current and 0.5 mV maximum offset voltage.
Low Noise Preamplifiers
High Performance Audio
The internal compensation of the AD745 is optimized for higher
gains, providing a much higher bandwidth and a faster slew
rate. This makes the AD745 especially useful as a preamplifier
where low level signals require an amplifier that provides both
high amplification and wide bandwidth at these higher gains.
The AD745 is available in two performance grades. The AD745J
and AD745K are rated over the commercial temperature range
of 0°C to 70°C, and are available in the 16-lead SOIC package.
PRODUCT DESCRIPTION
The AD745 is an ultralow noise, high-speed, FET input opera-
tional amplifier. It offers both the ultralow voltage noise and
high speed generally associated with bipolar input op amps and
the very low input currents of FET input devices. Its 20 MHz
bandwidth and 12.5 V/µs slew rate makes the AD745 an ideal
120
100
80
120
100
80
1000
R
SOURCE
OP37 AND
RESISTOR
E
PHASE
GAIN
O
R
SOURCE
100
10
1
60
60
AD745 AND RESISTOR
OR
OP37 AND RESISTOR
AD745 AND
RESISTOR
40
40
20
20
0
0
RESISTOR NOISE ONLY
1k 10k
–20
100M
–20
100
100
100k
1M
10M
1k
10k
100k
1M
10M
SOURCE RESISTANCE – ꢁ
FREQUENCY – Hz
Figure 1.
Figure 2.
REV. D
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