REV. A
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reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
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a
OP37
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 2002
Low Noise, Precision, High Speed
Operational Amplifier (A
VCL
>
5)
SIMPLIFIED SCHEMATIC
V–
V+
Q2B
R2*
Q3
Q2AQ1A Q1B
R4
R1*
R3
18
V
OS
ADJ.
R1 AND R2 ARE PERMANENTLY
ADJUSTED AT WAFER TEST FOR
MINIMUM OFFSET VOLTAGE.
*
NON-INVERTING
INPUT (+)
INVERTING
INPUT (–)
Q6
Q21
C2
R23 R24
Q23
Q24
Q22
R5
Q11 Q12
Q27 Q28
C1
R9
R12
C3 C4
Q26
Q20 Q19
Q46
Q45
OUTPUT
FEATURES
Low Noise, 80 nV p-p (0.1 Hz to 10 Hz)
3 nV/√Hz @ 1 kHz
Low Drift, 0.2 V/ⴗC
High Speed, 17 V/s Slew Rate
63 MHz Gain Bandwidth
Low Input Offset Voltage, 10 V
Excellent CMRR, 126 dB (Common-Voltage @ 11 V)
High Open-Loop Gain, 1.8 Million
Replaces 725, OP-07, SE5534 In Gains > 5
Available in Die Form
GENERAL DESCRIPTION
The OP37 provides the same high performance as the OP27,
but the design is optimized for circuits with gains greater than
five. This design change increases slew rate to 17 V/µs and
gain-bandwidth product to 63 MHz.
The OP37 provides the low offset and drift of the OP07
plus higher speed and lower noise. Offsets down to 25 µV and
drift
of 0.6 µV/°C maximum make the OP37 ideal for preci-
sion
instrumentation applications. Exceptionally low noise
(e
n
=
3.5 nV/ @ 10 Hz), a low 1/f noise corner frequency of
2.7 Hz,
and the high gain of 1.8 million, allow accurate
high-gain amplification of low-level signals.
The low input bias current of 10 nA and offset current of 7 nA
are achieved by using a bias-current cancellation circuit.
Over
the military temperature range this typically holds I
B
and I
OS
to 20 nA and 15 nA respectively.
PIN CONNECTIONS
8-Lead Hermetic DIP
(Z Suffix)
Epoxy Mini-DIP
(P Suffix)
8-Lead SO
(S Suffix)
8
7
6
5
1
2
3
4
NC = NO CONNECT
V
OS
TRIM
–IN
+IN
V
OS
TRIM
V+
OUT
NCV–
OP37
The output stage has good load driving capability. A guaranteed
swing of 10 V into 600 Ω and low output distortion make the
OP37 an excellent choice for professional audio applications.
PSRR and CMRR exceed 120 dB. These characteristics, coupled
with long-term drift of 0.2 µV/month, allow the circuit
designer
to achieve performance levels previously attained only by
discrete designs.
Low-cost, high-volume production of the OP37 is achieved
by
using on-chip zener-zap trimming. This reliable and stable
offset
trimming scheme has proved its effectiveness over many
years of
production history.
The OP37 brings low-noise instrumentation-type performance
to
such diverse applications as microphone, tapehead, and RIAA
phono preamplifiers, high-speed signal conditioning for data
acquisition systems, and wide-bandwidth instrumentation.
