LG GB210 - Battery Charging

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. TECHNICAL BRIEF
The ISL9221 accepts two power inputs, normally one from a USB port and the other from a TA.
Charging Process
- Connecting TA & Charger Detection
- Control the charging Current by U303(Charger IC)
- Charging Current flows into the Battery.
Pins of U304 used for charging
-VDC : Charger supply.
- VUSB_IN : USB charging supply.
- IMIN: IMIN is the programmable input for the end-of-charge current.
- IVDC: Program the TA charge current during the constant current mode.
- IUSB : Program the USB charge current during the constant current mode.
- _EN :Enable logic input
- BAT : Charger output pin.
- USB_BYP : Output pin from USB bypass circuitry
- VDC_BYP : Output Pin of Linear Regulator
TA (Travel Adaptor)
- Input voltage: AC 100V ~ 240V, 50/60Hz
- Output voltage: DC 5.1V
- Output current: Max 700mA
Battery
- Li-ion battery (Max 4.2V, Nom 3.7V)
- Standard battery: Capacity - 1100mAh
Figure 3.15 CIRCUIT FOR BATTERY CHARGING
Charging current
flow
3.15 Battery Charging
EUSY0351601
1%
CHARGE(TA+USB)
VCHG_IN
OVP_VCHG
R339
10K
C350
1u
C352
1u
VBUS_IN
R341
18K
10K
R340
U303
BAT
11
8
GND
6
IMIN
7
IUSB
9
IVDC
PGND
13
USB_BYP
10
1
VDC
12
VDC_BYP
VUSB
2
4
_CHG
5
_EN
_PPR
3
ISL9221
100K
R338
VBAT
OVP_VUSB
C351
1u
_CHG_EN
Charging current
fl ow