AD8213YRMZ-RL(Rev0) View Datasheet(PDF) - Analog Devices
Part Name
Description
Manufacturer
AD8213YRMZ-RL Datasheet PDF : 16 Pages
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AD8213
APPLICATIONS INFORMATION
HIGH-SIDE CURRENT SENSE WITH A LOW-SIDE
SWITCH
In such load control configurations, the PWM controlled switch
is ground referenced. An inductive load (solenoid) is tied to a
power supply. A resistive shunt is placed between the switch and
the load (see Figure 28). An advantage of placing the shunt on
the high side is that the entire current, including the recircu-
lation current, can be measured, because the shunt remains in
the loop when the switch is off. In addition, diagnostics can be
enhanced because shorts to ground can be detected with the
shunt on the high side. In this circuit configuration, when the
switch is closed, the common-mode voltage moves down to
near the negative rail. When the switch is opened, the voltage
reversal across the inductive load causes the common-mode
voltage to be held one diode drop above the battery by the
clamp diode.
BATTERY
INDUCTIVE
LOAD
CLAMP
DIODE
SHUNT
SWITCH
AD8213
1 –IN2
2 +IN2
3 GND
4 OUT2
5 CF2
–IN1 10
+IN1 9 5V
V+ 8
OUT1 7
CF1 6
CAP2
CAP1
INDUCTIVE
LOAD
CLAMP
DIODE
SHUNT
BATTERY
SWITCH
Figure 28. Low-Side Switch
HIGH-SIDE CURRENT SENSING
In this configuration, the shunt resistor is referenced to the
battery. High voltage will be present at the inputs of the current
sense amplifier. In this mode, the recirculation current is again
measured and shorts to ground can be detected. When the
shunt is battery referenced the AD8213 produces a linear
ground referenced analog output. An AD8214 can also be used
to provide an overcurrent detection signal in as little as 100 ns.
This feature will be useful in high current systems, where fast
shutdown in overcurrent conditions is essential.
SHUNT
LOAD
SWITCH
OVERCURRENT
DETECTION (<100ns)
8
7
6
5
–IN NC GND OUT
AD8214
VS +IN VREG NC
1
2
3
4
OVERCURRENT
DETECTION (<100ns)
5
6
7
8
OUT GND NC –IN
AD8214
NC VREG +IN VS
4
3
2
1
AD8213
1 –IN2
–IN1 10
2 +IN2
+IN1 9
5V
3 GND
V+ 8
4 OUT2 OUT1 7
5 CF2
CF1 6
CAP2
CAP1
SHUNT
LOAD
SWITCH
Figure 29. Battery Referenced Shunt Resistor
LOW-SIDE CURRENT SENSING
In systems where low-side current sensing is preferred, the
AD8213 provides an integrated solution with great accuracy.
Ground noise is rejected, CMRR is typical higher than 90 dB, and
output linearity is not compromised, regardless of the input
differential voltage.
BATTERY
INDUCTIVE
LOAD
CLAMP
DIODE
SWITCH
SHUNT
AD8213
1 –IN2
2 +IN2
3 GND
4 OUT2
5 CF2
–IN1 10
+IN1 9 5V
V+ 8
OUT1 7
CF1 6
INDUCTIVE
LOAD
CLAMP
DIODE
SWITCH
BATTERY
SHUNT
Figure 30. Ground Referenced Shunt Resistor
Rev. 0 | Page 12 of 16
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