Datasheet

AD8217
Rev. A | Page 12 of 16
APPLICATIONS INFORMATION
HIGH-SIDE CURRENT SENSING
In this configuration, the shunt resistor is referenced to the
battery (see Figure 26). High voltage is present at the inputs
of the current sense amplifier. When the shunt is battery
referenced, the AD8217 produces a linear ground-referenced
analog output. The AD8217 includes an internal LDO, which
allows the part to be powered from the high voltage rail, with
no need for an additional standalone supply.
+IN
I
LOAD
SHUNT
GND
–IN
ADC
4.5
V
TO
80V
AD8217
OUT
09161-026
Figure 26. Battery-Referenced Shunt Resistor
MOTOR CONTROL CURRENT SENSING
The AD8217 is a practical, accurate solution for high-side
current sensing in motor control applications. In cases where
the shunt resistor is referenced to battery and the current
flowing is unidirectional (as shown in Figure 27), the AD8217
monitors the current with no additional supply pin necessary.
+IN
GND
–IN
B
A
TTE
R
Y
MOTOR
I
MOTOR
AD8217
OUT
09161-027
Figure 27. High-Side Current Sensing in Motor Control