Precision Picoampere Input Current
Quad Operational Amplifier
OP497
FEATURES
Low offset voltage: 75 μV maximum
Low offset voltage drift: 1.0 μV/°C maximum
Very low bias current
25°C: 150 pA maximum
−40°C to +85°C: 300 pA maximum
Very high open-loop gain: 2000 V/mV minimum
Low supply current (per amplifier): 625 μA maximum
Operates from ±2 V to ±20 V supplies
High common-mode rejection: 114 dB minimum
PIN CONNECTIONS
OUT A
–IN A
+IN A
V+
+IN B
–IN B
OUT B
NC
1
2
3
4
5
6
7
8
16
15
14
OUT D
–IN D
+IN D
V–
+IN C
–IN C
OUT C
00309-001
00309-002
OP497
13
12
11
10
9
NC
NC = NO CONNECT
Figure 1. 16-Lead Wide Body SOIC (RW-16)
APPLICATIONS
Strain gage and bridge amplifiers
High stability thermocouple amplifiers
Instrumentation amplifiers
Photocurrent monitors
High gain linearity amplifiers
Long-term integrators/filters
Sample-and-hold amplifiers
Peak detectors
Logarithmic amplifiers
Battery-powered systems
INPUT CURRENT (pA)
OUT A
–IN A
+IN A
V+
+IN B
–IN B
OUT B
1
2
3
4
5
6
7
14
13
12
OUT D
–IN D
+IN D
V–
+IN C
–IN C
OUT C
OP497
11
10
9
8
Figure 2. 14-Lead PDIP (N-14)
1k
V
S
= ±15V
V
CM
= 0V
GENERAL DESCRIPTION
The OP497 is a quad op amp with precision performance in
the space-saving, industry standard 16-lead SOlC package.
Its combination of exceptional precision with low power and
extremely low input bias current makes the quad OP497 useful
in a wide variety of applications.
Precision performance of the OP497 includes very low offset
(<50 μV) and low drift (<0.5 μV/°C). Open-loop gain exceeds
2000 V/mV ensuring high linearity in every application. Errors
due to common-mode signals are eliminated by its common-
mode rejection of >120 dB. The OP497 has a power supply
rejection of >120 dB which minimizes offset voltage changes
experienced in battery-powered systems. The supply current
of the OP497 is <625 μA per amplifier, and it can operate with
supply voltages as low as ±2 V.
The OP497 uses a superbeta input stage with bias current
cancellation to maintain picoamp bias currents at all temperatures.
This is in contrast to FET input op amps whose bias currents
start in the picoamp range at 25°C but double for every 10°C
rise in temperature to reach the nanoamp range above 85°C.
The input bias current of the OP497 is <100 pA at 25°C.
100
–I
B
+I
B
I
OS
–50
–25
0
25
50
75
100
125
00309-003
10
–75
TEMPERATURE (°C)
Figure 3. Input Bias, Offset Current vs. Temperature
Combining precision, low power, and low bias current, the OP497
is ideal for a number of applications, including instrumentation
amplifiers, log amplifiers, photodiode preamplifiers, and long-
term integrators. For a single device, see the
data sheet,
and for a dual device, see the
data sheet.
Rev. E
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 that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
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Tel: 781.329.4700
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Fax: 781.461.3113 ©1991–2009 Analog Devices, Inc. All rights reserved.
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