User Guide

Figure 22 Battery pin order

The battery temperature can be measured from the UI flex.

Battery connector

The battery connector is a blade connector. It has three blades;

• BSI (Battery size indicator)

• GND (Ground)

• VBAT (Battery voltage)

The BSI line is used to recognize the battery capacity by a battery internal pull down resistor.

Figure 23 Battery connector

Charging

This phone is charged through a separate charger 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 two Application Specific Integrated Circuits (ASICs) N2300

BETTY and N2200 AVILMA. These two circuits contains a number of regulators. In addition there are some

external regulators too.

In the table below normal and extreme voltages are shown when a BL-4CT battery is used.

Table 7 Nominal voltages

Voltage Voltage [V] Condition

General Conditions

Nominal voltage 4.0

Lower extreme voltage 3.145

Higher extreme voltage (fast

charging) 4.230

HW Shutdown Voltages

Vmstr+ 2.1 ± 0.1 Off to on

Vmstr- 1.9 ± 0.1 On to off

RM-378; RM-379

System Module

Issue 1 COMPANY CONFIDENTIAL Page 5 –9