Preliminary Technical Data
EXTERNAL REFERENCE OUTPUT
Tying both pins together and to a reference produces an output
at the reference voltage when there is no differential input (see
Figure 4). The output moves down from the reference voltage
when the input is negative relative to the 鈭捍N pin and up when
the input is positive relative to the 鈭捍N pin.
Rs
+IN
-IN
Vs
AD8210
SPLITTING THE SUPPLY
By tying one reference pin to V+ and the other to the ground
pin, the output is set at half of the supply when there is no
differential input (see Figure 6). The benefit is that no external
reference is required to offset the output for bidirectional
current measurement. This creates a midscale offset that is
ratiometric to the supply, which means that if the supply increases
or decreases, the output remains at half the supply. For example, if
the supply is 5.0 V, the output is at half scale or 2.5 V. If the supply
increases by 10% (to 5.5 V), the output goes to 2.75 V.
Rs
+IN
-IN
Vs
AD8210
VRef 1
G=20
2.5V
V Out
VRef 2
GND
AD8210
V Ref 1
Figure 4. External Reference Output
V Out
G=20
SPLITTING AN EXTERNAL REFERENCE
In this case, an external reference is divided by 2 with an
accuracy of approximately 0.5% by connecting one V
REF
pin to
ground and the other V
REF
pin to the reference (see Figure 17).
Rs
+IN
-IN
Vs
V Ref 2
GND
Figure 6: Split Supply
AD8210
5V
VRef 1
G=20
V Out
VRef 2
GND
Figure 5: Split External Reference
Rev. PrA | Page 5 of 8