Low-Noise, Precision
Operational Amplifier
a
OP27
PIN CONNECTIONS
FEATURES
Low Noise: 80 nV p-p (0.1 Hz to 10 Hz), 3 nV/
Low Drift: 0.2 ꢀV/ꢁC
High Speed: 2.8 V/ꢀs Slew Rate, 8 MHz Gain
Bandwidth
√Hz
TO-99
(J-Suffix)
BAL
Low VOS: 10 ꢀV
Excellent CMRR: 126 dB at VCM of 11 V
High Open-Loop Gain: 1.8 Million
Fits 725, OP07, 5534A Sockets
Available in Die Form
V+
BAL 1
OP27
OUT
–IN 2
NC
+IN 3
GENERAL DESCRIPTION
4V– (CASE)
NC = NO CONNECT
The OP27 precision operational amplifier combines the low
offset and drift of the OP07 with both high speed and low noise.
Offsets down to 25 µV and drift of 0.6 µV/°C maximum make
the OP27 ideal for precision instrumentation applications.
Exceptionally low noise, en = 3.5 nV/√Hz, at 10 Hz, a low 1/f
noise corner frequency of 2.7 Hz, and high gain (1.8 million),
allow accurate high-gain amplification of low-level signals. A
gain-bandwidth product of 8 MHz and a 2.8 V/µsec slew rate
provides excellent dynamic accuracy in high-speed, data-
acquisition systems.
8-Pin Hermetic DIP
(Z-Suffix)
Epoxy Mini-DIP
(P-Suffix)
8-Pin SO
(S-Suffix)
A low input bias current of 10 nA is achieved by use of a
bias-current-cancellation circuit. Over the military temperature
range, this circuit typically holds IB and IOS to 20 nA and 15 nA,
respectively.
1
2
3
4
8
7
6
5
V
TRIM
V
TRIM
–IN
+IN
V–
OS
OS
OP27
V+
OUT
NC
The output stage has good load driving capability. A guaranteed
swing of 10 V into 600 Ω and low output distortion make the
NC = NO CONNECT
OP27 an excellent choice for professional audio applications.
(Continued on page 7)
V+
C2
R3
R4
1
8
Q6
Q22
Q46
C1
V
ADJ.
OS
R23 R24
Q24
R1*
R2*
Q21
Q23
R9
Q20 Q19
OUTPUT
R12
Q1A Q1B
Q2B Q2A
NONINVERTING
INPUT (+)
C3
C4
R5
Q3
Q26
INVERTING
INPUT (–)
Q45
Q11 Q12
Q27
Q28
*R1 AND R2 ARE PERMANENTLY
ADJUSTED ATWAFERTEST FOR
MINIMUM OFFSETVOLTAGE.
V–
Figure 1. Simplified Schematic
REV. A
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may result from its use. No license is granted by implication or otherwise
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© Analog Devices, Inc., 2002