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LGE Internal Use Only
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
Constant Current Charging
The PM7540 IC supports constant current charging of the main battery by controlling the charger pass
transistor and the battery transistor. The constant current charging continues until the battery reaches
its target voltage, 4.2V.
Constant Voltage Charging
Constant voltage charging begins when the battery voltage reaches a target voltage, 4.2V.
The end of constant voltage charging is commonly detected 10% of the full charging current.
• Charging Method : CC & CV (Constant Current & Constant Voltage)
• Maximum Charging Voltage : 4.2V
• Maximum Charging Current : 660mA
• Nominal Battery Capacity : 900mAh
• Charging time : Max. 3h 30m
• Full charge indication current (icon stop current) : 50mA
• Cut-off voltage : 3.30V
3. Technical Brief
Indication
Standby
Bar3
3.75
ᇹ
0.05V
決旇
Bar 3
˧
2
3.75
ᇹ
0.05V
Bar 2
˧
1
3.67
ᇹ
0.05V
Bar 1
˧
Blink
3.6
ᇹ
0.05V
Low Voltage,
Warning Blinking
3.6
ᇹ
0.05V (Stand-by) /
3.6
ᇹ
0.05V (Talk)
[Interval : 3min(Stand-by) / 1min(Talk)]
Power Off
3.3
ᇹ
0.05V
Battery icon display
≥