LG GS290 Service Manual page 33

3. TECHNICAL BRIEF
GS290 Operational Description
3.3.2. Charging
The bq25040 has a single power output that charges the battery. A system load can be placed in parallel with
the battery.The charge current is programmed using the ISET and EN/SET inputs. The charge current is
programmable to USB100, USB500 or a user programmed charge current up to 1.2A. Additionally, a 4.9V +/-3%
50mA LDO is integrated into the IC for supplying low power external circuitry. The one-wire interface (EN/SET)
is available to place the bq25040 into Test Jig Mode. In Test Jig Mode, the output is regulated at 4.2V and can
be used without a battery.The bq25040 has a single power output that charges the battery.. Either a 1-cell
Li-Ion or Li-Ion-Polymer battery with 4.1, 4.2 or 4.4 Volts may be used.
4.2V~3.74V
Figure 5 Battery Block Indication
1. Charging method : CC-CV
2. Charger detect voltage : 4.8 V
3. Charging time : 2h
4. Charging current : 645 mA
5. CV voltage : 4.2 V
6. Cutoff current : 105 mA
7. Full charge indication current (icon stop current) : 110 mA
8. Recharge voltage : 4.16 V
9. Low battery alarm
a. Stand by : 3.59V ±0.05V
b. Call : 3.59V ±0.05V
10. Low battery alarm interval
a. Stand by : 3 min
b. Dedicated : 1 min
11. Switch-off voltage : 3.35 V
LGE Internal Use Only
LG Electronics
3.73V~3.65V 3.65V~3.59V 3.59V~3.35V
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