OP97EJ AD [Analog Devices], OP97EJ Datasheet - Page 11

• Manufacturer Part Number: OP97EJ
• Description: LOW POWER, HIGH PRECISION OPERATIONAL AMPLIFIER
• Manufacturer: AD [Analog Devices]

APPLICATION INFORMATION
The OP97 is a low power alternative to the industry-standard
precision op amp, the OP07. The OP97 can be substituted
directly into OP07, OP77, AD725, and PM1012 sockets with
improved performance and/or less power dissipation and can be
inserted into sockets conforming to the 741 pinout if nulling
circuitry is not used. Generally, nulling circuitry used with earlier
generation amplifiers is rendered superfluous by the extremely
low offset voltage of the OP97 and can be removed without
compromising circuit performance.
Extremely low bias current over the full military temperature
range makes the OP97 attractive for use in sample-and-hold
amplifiers, peak detectors, and log amplifiers that must operate
over a wide temperature range. Balancing input resistances is
not necessary with the OP97. Offset voltage and TCV
degraded only minimally by high source resistance, even when
unbalanced.
OS
are
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The input pins of the OP97 are protected against large
differential voltage by back-to-back diodes. Current-limiting
resistors are not used to maintain low noise performance. If
differential voltages above ±1 V are expected at the inputs,
series resistors must be used to limit the current flow to a
maximum of 10 mA. Common-mode voltages at the inputs are
not restricted and may vary over the full range of the supply
voltages used.
The OP97 requires very little operating headroom about the
supply rails and is specified for operation with supplies as low as
±2 V. Typically, the common-mode range extends to within 1 V
of either rail. The output typically swings to within 1 V of the
rails when using a 10 kΩ load.
Offset nulling is achieved utilizing the same circuitry as an
OP07. A potentiometer between 5 kΩ and 100 kΩ is connected
between Pin 1 and Pin 8 with the wiper connected to the
positive supply. The trim range is between 300 μV and 850 μV,
depending upon the internal trimming of the device.
Figure 29. Optional Input Offset Voltage Nulling
and Overcompensation Circuit
2
3
OP97
1
–V
4
8
5
7
C
R
OC
POT
6
= 5kΩ TO 100kΩ
+V
OP97