Battery Charging Block - LG KG920 Service Manual

3.7 Battery Charging Block

(GPIO_0) CHG_EN
The ISL6299 is designed for a single-cell Li-ion or Li-polymer battery charging circuit that accepts both
a USB port and a desktop cradle as its power source.
Input Auto Selection
When both input sources are present, the charger selects only one power source to charge the
battery. When the CRDL input is higher than the POR threshold, CRDL is selected as the power
source. Otherwise the USB input is selected. If the CRDL input voltage is below the battery voltage but
the USB input voltage is higher than the battery voltage, then the USB input is used to charge the
battery. The control circuit always cuts both internal power devices off before switching from one
power source to the other to avoid a cross conduction of both power MOSFETs.
Charging IC
VCHARGE
VUSBIN VUSBIN
R215
0
C236 C237
(1%)
1u 1u
Figure 3-18. CIRCUIT FOR BATTERY CHARGING
- 43 -
3. TECHNICAL BRIEF
VBAT
D201
CUS02
U206 ISL6299
1 10
CRDL BAT
2
USB
6 3
IMIN _PPR
4
_CHG
9
ICDL
7 8
USBON GND
5 11
_EN PGND
2V8_VEXT
(GPIO_16)
CHG_STAT
C238 C239
1u 27p