Energy management
Battery and charging
BL-4D battery
The phone is powered by a 3-pole BL-4D battery 1200 mAh battery. 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 43 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 44 Blade battery connector
Charging
This phone is charged through the micro USB connector. Charging is controlled by energy management, and
external components are needed to protect the baseband module against EMC, reverse polarity and transient
frequency deviation.
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 BL-4D battery is used.
Table 10 Nominal voltages
Voltage
Voltage [V]
Condition
General Conditions
Nominal voltage
3.700
RM-626
System Module
Page 6 – 12
COMPANY CONFIDENTIAL
Issue 1
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