Only For Training And Service Purposes - LG GD580 Service Manual

3.5.1 Fuel Gauge
AB3000 supports the measurement of the current consumption/charging current in the GD580
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.3-5-3). 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.
Figure 3-5-3. The analog front-end of the fuel gauge block
C 4 0 1 C 4 2 5
3 3 u
2 2 p
Name
FGSENSE+
FGSENSE-
Copyright © 2009 LG Electronics. Inc. All right reserved.

Only for training and service purposes

R
B t a e t y r C o n . n
2 0 1 2 R 4
P h o n e g o r u n d 1 %
2 5
1 4 / W
e r u t n r p a h t
C 4 4 3
2 2 p
B A T T _ G N D
Figure 3-5-4 The Schematic of the fuel gauge block
Type Unused
Analog VBAT
Analog VBAT
Table 3-5-2. Fuel Gauge channel spec
T C _ G N D G | N D _ D G I T I A L
R 4 4 0
0
3 3
C o l s e o t P n i 3
o r u e t a s a d f i e f
M
R 4 3 9
0
Description
Fuel gauge current sensing input positive
Fuel gauge current sensing input negative
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3. Technical brief
H
G 1
C 4 0 2
e r n i t l a p a r i 4 7 p
C o l s e o t A B
G 1
LGE Internal Use Only
4
B D A T A
2
F G S E N S E +
1
F G S E N S E -