Datasheet

APPLICATION INFORMATION
V
CM)
+
(
V)
)
) 5
[(
V)
)
*
(
0.5V
REF
)]
(3)
V
CM*
+
(
V*
)
* 5
[(
0.5V
REF
)
*
(
V*
)]
(4)
COMMON-MODE RANGE
V
CM)
+
(
V)
)
) 5
[(
V)
)
* V
REF
]
(1)
V
CM*
+
(
V*
)
* 5
[
V
REF
*
(
V*
)]
(2)
INA159-EP
www.ti.com .......................................................................................................................................................................................... SBOS443 – NOVEMBER 2008
The internal op amp of the INA159 has a rail-to-rail
common-mode voltage capability at its inputs. A
rail-to-rail op amp allows the use of ± 10-V inputs into
Some typical values are shown in Table 1 .
a circuit biased to 1/2 of a 5-V reference (2.5-V
quiescent output). The inputs to the op amp will swing
Table 1. Common-Mode Range For Various
from approximately 400 mV to 3.75 V in this
Supply and Reference Voltages
application.
REF 1 and REF 2 Connected Together
The unique input topology of the INA159 eliminates
V+ V − V
REF
V
CM+
V
CM −
the input offset transition region typical of most
rail-to-rail complementary stage operational 5 0 3 15 – 15
amplifiers. This allows the INA159 to provide superior
5 0 2.5 17.5 – 12.5
glitch- and transition-free performance over the entire
5 0 1.25 23.75 – 6.25
common-mode range.
1/2 Reference Connection
Good layout practice includes the use of a 0.1- µ F
V+ V − V
REF
V
CM+
V
CM −
bypass capacitor placed closely across the supply
5 0 5 17.5 – 12.5
pins.
5 0 4.096 19.76 – 10.24
5 0 2.5 23.75 – 6.25
3.3 0 3.3 11.55 – 8.25
The common-mode range of the INA159 is a function
3.3 0 2.5 13.55 – 6.25
of supply voltage and reference. Where both pins,
3.3 0 1.25 16.675 – 3.125
REF1 and REF2, are connected together:
Where one REF pin is connected to the reference,
and the other pin grounded (1/2 reference
connection):
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Product Folder Link(s): INA159-EP