3. TECHNICAL BRIEF
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Copyright © 01 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Copyright © 2012 LG Electronics. Inc. All right reserved.
O nly for training and service purposes
LGE Internal Use Only
29
3. TECHNICAL BRIEF
3.9 Battery Charger Interface
The RT9524 is a fully integrated single-cell Li-Ion battery charger IC ideal for portable applications. The
RT9524 optimizes the charging task by using a control algorithm including pre-charge mode, fast charge
mode and constant voltage mode. the input voltage range of the VIN pin can be as high as 30V. When the
input voltage exceeds the OVP threshold, it will turn off the charging
MOSFET to avoid overheating of the chip. In RT9524, the maximum charging current can be
programmed with an external resister. For the USB application, user can set the current to
100mA/500mA through EN/SET pin. For the factory mode, the RT9524 can allow 4.2V/2.3A power pass
through to support system operation. It also provides a 50mA LDO to support the power of peripheral circuit.
The internal thermal feedback circuit regulates the die temperature to optimize
the charge rate for all ambient temperatures. The RT9524 provides protection functions such as under voltage
protection, over voltage protection for VIN supply and thermal protection for battery temperature.
The RT9524 is available in a WDFN-10L 2x3 package to achieve optimized solution for PCB space and thermal
considerations.
Figure 3.9.1. RT9524 Block Diagram
3.9 Battery Charger Interface
VIN
IEOC
Base
Switch
Well
Sleep
Mode
I
EOC
Set
Block
OVP
UVLO
Logic
V
REF
V
DD
I
Bias
CC/CV/TR
Multi Loop
Controller
Status
Current
Set Block
Current
Set Block
3-- LDO
LDO
EN/SET
ISET
GND
PGB
CHGSB
BATT