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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
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3.11 Battery Charger Interface
Figure 3-11-1 BATTERY CHARGER BLOCK
The ISL9221 Lithium Ion charging IC is designed to meet the charging requirements of most of today’s
handheld devices. The IC provides two inputs for either USB connection where the current is limited by the
USB standard or for powering/charging from a power adapter.
If the voltage at either VUSB or VDC pin is within the safe allowable range, the PPR pin is pulled low
indicating to the system processor that external power is available.
Charging can be enabled/disabled by controlling the state of the EN pin. While charging, the CHG pin is
pulled low indicating the battery is being charged.
The battery is charged to 4.2V with only a 1% error across the temperature range. USB charge current,
Adapter charge current and charge termination currents can be programmed via external resistors.
The ISL9221 adds an additional feature in providing a limited amount of current to system architecture
while protecting the system from destructively high voltage.
The device contains Thermal regulation and protection to provide additional safety features of this device.
When the temperature e125
°
C, the current will fold back to reduce and control the die
temperature.
From External Source
(Wall Adaptor or Computer)
External Charger
VBAT
100K
R212
C220
1u
CHG_ABB
15K
R217
_CHG
4
_EN
5
3
_PPR
BAT
11
8
GND
6
IMIN
IUSB
7
IVDC
9
13
PGND
10
USB_BYP
VDC
1
VDC_BYP
12
2
VUSB
ISL9221
U202
VBUS_USB
R213
100K
R222
18K
1u
C222
C224
1u
R216
10K
R220
18K
VCHARGE
100K
R218
2V93_VEXT
VUSBIN
R219
5.62K
1u
C221
1u
C223
CHG_PPR
CHG_IND
CHG_EN
USB_DET
From
External
Source
(Wall
Adaptor
or
Computer)