Backup Battery; Normal And Extreme Voltages - Nokia MOBILE TERMINAL Service Manual

RM-356
System Module and User Interface
• GND (Ground)
• 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 the smaller Nokia standard interface (2.0 mm plug). The wider standard
charger (3.5 mm) can be used together with the CA-44 charger adapter.
Charging is controlled by energy management, and external components are needed to protect the baseband
module against EMC, reverse polarity and transient frequency deviation.

Backup battery

When the main battery is not attached EM ASIC (N2200) goes in backup mode using back-up battery that
supplies voltage to RTC in EM ASIC (N2200).

Normal and extreme voltages

Energy management is mainly carried out in the two Application Specific Integrated Circuits (ASICs) BETTY
and 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-5J S-pack battery is used.
Voltage
Nominal voltage
Lower extreme voltage
Higher extreme voltage
(fast charging)
Vmstr+
Vmstr-
Sw shutdown
Issue 1
Figure 53 Small (right) and wide (left) charger plugs
Table 14 Nominal voltages
Voltage [V]
General Conditions
3.700
3.145
4.230
HW Shutdown Voltages
2.1 ± 0.1
1.9 ± 0.1
SW Shutdown Voltages
3.15
COMPANY CONFIDENTIAL
Copyright © 2008 Nokia. All rights reserved.
Condition
Off to on
On to off
In call
Page 6 –9