Energy Management; Battery And Charging; Normal And Extreme Voltages - Nokia RM-609 Service Manual

RM-609
System Module

Energy management

Battery and charging

BP-4L battery
The phone is powered by a 3-pole BP-4L battery 1500 mAh. The three poles are named VBAT, BSI and GND
where the BSI line is used to recognize the battery capacity. This is done by means of an internal battery pull
down resistor.
Figure 40 Battery pin order
The battery temperature is estimated by measuring separate temperature NTC resistor via the BTEMP line of
EM ASIC N2200. This is located on the main PWB, near the battery connector.
Battery connector
The battery connector is a blade connector. It has three blades:
• BSI (Battery size indicator)
• GND (Ground)
• VBAT (Battery voltage)
Figure 41 Blade battery connector
Charging
The phone is charged through the 2 mm Nokia standard interface charger plug. Charging is controlled by
dynamo charging IC BQ24156 (N3323). Dynamo charger detection is handled by EM ASIC (N2200) and external
components are needed to protect the baseband module against EMC, reverse polarity and transient
frequency deviation. For charger detection, a pulse of duration 15ms is sent to EM ASIC via V3370 MOSFET.

Normal and extreme voltages

Energy management is mainly carried out in the EM ASIC (N2200). that contains a number of regulators. In
addition there are also some external regulators.
In the table below normal and extreme voltages are shown when a BP-4L battery is used.
Table 10 Nominal voltages
Voltage Voltage [V] Condition
General Conditions
Nominal voltage 3.700
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