LG W3000 Service Manual page 40

Power up sequence logic
The ADP3408 controls power on sequence If a battery is inserted, the battery powers the 6 LDOs.
Then if PWRONKEY is detected, the LDOs output turn on.
Reset is generated and send to the AD6522
Battery charging block(the phones use Li-Ion battery only.)
Charger initialization, trickle charging, and Li-Ion charging control are implemented in hardware.
Charging Process
1. Check charger is inserted or not
2. If ADP3408 detects that Charger is inserted, AD3408 Detect Signal output is HIGH
3. Start CC charging (HIGHCURRENT CHARGE MODE)
4. if VBAT>4.2V, end of charge, then EOC(AD3408Output) is HIGH
if VBAT < UVLO, then charging in Low Current Charge Mode, until VBAT > UVLO(Under
voltage lock out)
The Status of charging is displayed in the LCD by connecting MVBAT in AD3408 and AD6521.
Pins used for charging
CHG_DET : Interrupt to AD6522 when charger is plugged.
CHG_EN : Control signal from AD6522 to charge Li+ battery
EOC : Interrupt to AD6522 when battery is fully charged
GATEIN : Control signal from AD6522 to charge NiMH battery. But, not used.
MVBAT : Battery voltage divider. Divide ratio is 1:2.3 and it is sensed in AD6521 AUX_ADC
TA (Travel Adaptor)
Input voltage : AC 85V ~ 260V, 50~60Hz
Output voltage : DC 5.2V(æ0.2 V), Output current: Max 850mA(æ50mA )
Battery
Li-ion battery(Max 4.2V, Nom 4.0V, Capacity - 850mAh)
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3. TECHNICAL BRIEF