LMP8602MM Datasheet, PDF (23/33 Pages) Texas Instruments – 60V Common Mode, Fixed Gain, Bidirectional Precision Current Sensing Amplifier

LMP8602, LMP8602Q, LMP8603, LMP8603Q
www.ti.com
SNOSB36D – JULY 2009 – REVISED MARCH 2013
BATTERY CURRENT MONITOR APPLICATION
This application example shows how the LMP8602/LMP8603 can be used to monitor the current flowing in and
out a battery pack. The fact that the LMP8602/LMP8603 can measure small voltages at a high offset voltage
outside the parts own supply range makes this part a very good choice for such applications. If the load current
of the battery is higher then the charging current, the output voltage of the LMP8602/LMP8603 will be above the
“half offset voltage” for a net current flowing out of the battery. When the charging current is higher then the load
current the output will be below this “half offset voltage”.
I_Charge
I_Load
Charger
I_Charge - I_Load
LOAD
V_S
OFFSET
7
R_SENSE
+IN 8
Level
1 ^shift
-IN
+
Preamplifier
Gain = 10
-
Internal
Resistor
100 k:
3
A1
Output Buffer
Gain = K2
4
A2
5 _OUT
C1
Figure 53. Battery Current Monitor Application
ADVANCED BATTERY CHARGER APPLICATION
The above circuit can be used to realize an advanced battery charger that has the capability to monitor the exact
net current that flows in and out the battery as show in Figure 54. The output signal of the
LMP8602/LMP8602Q/LMP8603/LMP8603Q is digitized with the A/D converter and used as an input for the
charge controller. The charge controller can be used to regulate the charger circuit to deliver exactly the current
that is required by the load, avoiding overcharging a fully loaded battery.
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