• VBAT (Battery voltage)
The BSI line is used to recognize the battery capacity by a battery internal pull down resistor.
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-4S 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
SW Shutdown Voltages
Sw shutdown
3.106
In call
Sw shutdown
3.2
In idle
Min Operating Voltage
Vcoff+
2.9 ± 0.1
Off to on
Vcoff-
2.6 ± 0.1
On to off
Power key and system power-up
When the battery is placed in the phone the power key circuits are energized. When the power key is pressed,
the system boots up (if an adequate battery voltage is present).
Power down can be initiated by pressing the power key again (the system is powered down with the aid of
SW). The power key is connected to EM ASIC N2200 (AVILMA) via PWRONX signal.
Modes of operation
Mode
Description
NO_SUPPLY
(dead) mode means that the main battery is not present or its voltage is too low (below
N2200 AVILMA master reset threshold) and that the back-up battery voltage is too low.
RM-352; RM-354
System Module
Issue 1
COMPANY CONFIDENTIAL
Page 5 –9
Copyright © 2008 Nokia. All rights reserved.
