LOAD

Charger

C1

+IN

-IN

+

-

Preamplifier

Output Buffer

Gain = K2

A1

A2

Gain = 10

OFFSET

Internal

Resistor

100 k:

OUT

Level

shift

1

5

3

4

7

8

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”.

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.

Copyright © 2009–2013, Texas Instruments Incorporated

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Product Folder Links: LMP8602 LMP8602Q LMP8603 LMP8603Q