Fuel Gauge - LG KU580 Service Manual

3.5.1 Fuel Gauge

AB2010 supports the measurement of the current consumption/charging current in the U8100 with a
fuel gauge block. By constantly integrating the current flowing into and out of the battery, the fuel
gauge block is used to determine the remaining battery capacity.
The function of the fuel gauge block is schematically described in (Fig.2-5-3). A sense resistor
R_FGSENSE is connected in series with the battery. The voltage across the resistor, equivalent to the
current entering/leaving the battery, is integrated using an ADC block.
Name
FGSENSE+
FGSENSE-
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Fig. 3-5-3. The analog front-end of the fuel gauge block
Fig. 3-5-4 The Schematic of the fuel gauge block
Type Unused
Analog VBAT
Analog VBAT
Table 3-5-2. Fuel Gauge channel spec
Description
Fuel gauge current sensing input positive
Fuel gauge current sensing input negative
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3. Technical Brief
LGE Internal Use Only