isl55002 Intersil Corporation, isl55002 Datasheet - Page 10

• Manufacturer Part Number: isl55002
• Description: High Supply Voltage 200mhz Unity-gain Stable Operational Amplifier
• Manufacturer: Intersil Corporation

Differential Output Instrumentation Amplifier
The addition of a third amplifier to the conventional three
amplifier instrumentation amplifier introduces the benefits of
differential signal realization, specifically the advantage of
using common-mode rejection to remove coupled noise and
ground potential errors inherent in remote transmission. This
configuration also provides enhanced bandwidth, wider
output swing and faster slew rate than conventional three
amplifier solutions with only the cost of an additional
amplifier and few resistors.
e
2
e
1
FIGURE 30. DIFFERENTIAL OUTPUT AMPLIFIER
R
V
G
R
R
+
+
-
-
A
1
A
2
2
2
1
1kΩ
R
1
R
R
3
3
R
R
1kΩ C
3
3
R
10
2
1nF
2
1nF
C
R
+
+
-
-
R
R
R
1kΩ
1
A
A
3
3
3
R
3
3
4
A
REF
FIGURE 29. SALLEN-KEY HIGH PASS FILTER
1kΩ
R
+
-
B
+
e
e
-
e
o
o
o
3
4
V+
V-
V
5V
V
5V
1nF
1nF
C
C
2
3
5
5
ISL55002
V
OUT
R
1kΩ
7
BW
Strain Gauge
The strain gauge is an ideal application to take advantage of
the moderate bandwidth and high accuracy of the ISL55002.
The operation of the circuit is very straightforward. As the
strain variable component resistor in the balanced bridge is
subjected to increasing strain, its resistance changes,
resulting in an imbalance in the bridge. A voltage variation
from the referenced high accuracy source is generated and
translated to the difference amplifier through the buffer
stage. This voltage difference as a function of the strain is
converted into an output voltage.
e
e
o3
o
=
=
=
–
2f
----------------- -
–
2 1
A
(
(
C1 2
1
Di
+
+
,
Holp
Q
Holp
Q
wo
wo
2R
2R
=
=
=
=
2
2
1 (
4
=
=
⁄
⁄
RC
R
−
R
−
K
2
R
4
2
A
G
K
G
K
1
K
Di
−
) e
C
) e
)
(
(
K
1
1
R
=
R
1
1
R
2
2
–
1
–
–
C
Equations simplify if we let
all components be equal R=C
C
C
2 1
e
e
2
1
2
2
(
2
)
)
+
+
1
2R
R
R
e
o4
1
2
2
C
C
⁄
2
1
R
=
G
+
(
)
1
R
+
R
2
2R
1
C
C
1
2
2
⁄
R
G
July 27, 2006
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(
FN7497.4
1
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)