Nokia 2608 Service Manual page 88

RM-376
System Module and User Interface
Figure 4 Simplied power flow diagram
Cha rger Detection
Co nnecting a charger creates a voltage on the DC_PWR of the Charging IC. Charging starts when the PM detects
the DC_PWR input voltage level between 4.35V~6.6V and /PGOOD pin pulls to GND (/PGOOD is pin 7of charging
IC). The charger detected when CHG_DEC_N_GPIO_53 pulls low (GND).
The battery is charged in three phases: conditioning, constant current , and constant voltage. In all charge
phases, an internal control loop monitors the IC junction temperature and reduces the charge current if the
internal temperature threshold is exceeded.
The charger power stage and charge current sense functions are fully integrated. The charger function has
high accuracy current and voltage regulation loops, charge status display, and charge termination. The input
current limit and charge current are programmable using external resistors.
Figure 5 Mobile terminal charger circuit
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