Datasheet
Output
INA21x
Load
Supply
ADC
V+
OUT
GND
IN-
IN+
C
BYPASS
0.01mF
to
0.1mF
+2.7Vto+26V
REF
R
1
R
3
R
2
R
4
R
SHUNT
INA210, INA211
INA212, INA213
INA214
www.ti.com
SBOS437E –MAY 2008–REVISED JUNE 2013
REF INPUT IMPEDANCE EFFECTS
As with any difference amplifier, the INA210-INA214 series common-mode rejection ratio is affected by any
impedance present at the REF input. This concern is not a problem when the REF pin is connected directly to
most references or power supplies. When using resistive dividers from the power supply or a reference voltage,
the REF pin should be buffered by an op amp.
In systems where the INA210-INA214 output can be sensed differentially, such as by a differential input analog-
to-digital converter (ADC) or by using two separate ADC inputs, the effects of external impedance on the REF
input can be cancelled. Figure 26 depicts a method of taking the output from the INA210-INA214 by using the
REF pin as a reference.
Figure 26. Sensing INA210-INA214 to Cancel Effects of Impedance on the REF Input
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Product Folder Links: INA210 INA211 INA212 INA213 INA214