Normal and extreme voltages
Energy management is mainly carried out in an Application Specific Integrated Circuit (ASIC) N2201 Loviisa.
This circuit contains a number of regulators.
In the table below normal and extreme voltages are shown when a BL-5C battery is used.
Table 11 Nominal voltages
Voltage Voltage [V] Condition
General Conditions
Nominal voltage 4.0
Lower extreme voltage 3.4
Higher extreme voltage (fast
charging) 4.2
HW Shutdown Voltages
Hw shutdown 2.9 GSM burst mode
Hw shutdown 3.0 idle mode
SW Shutdown Voltages
Sw shutdown 3.2 In idle
Sw shutdown 3.106 In call
Min Operating Voltage
Vcoff+ 3.2 Off to on
Vcoff- 2.62 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.
Modes of operation
Mode Description
NO_SUPPLY The battery is not present or it’s voltage is too low for the phone to turn on.
PWR_OFF The battery voltage is present and it’s voltage is over the 3.3V master reset threshold.
All the regulators are off. The PMU RTC is on and the 32 kHz oscillator is on but the PMU
is not sending the 32 kHz clock to the D2800 (BCM21351) and the BT/FM module.
CHARGING
(PWR_OFF)
The phone is turning on (if it is in PWR_OFF mode) when battery voltage is higher than
3.3V. The PMU will charge the battery up to 4.2V when the wall charger or USB cable is
plugged in.
[Comment: The phone may turn on into the NORMAL (PWR_ON) mode momentarily and
then go into a power saving mode (SLEEP). This will be determined by Nokia firmware.]
RESET Reset mode is a synonym for the startup sequence.
RM-497
System Module
Page 5 – 26 COMPANY CONFIDENTIAL Issue 1
Copyright © 2010 Nokia. All rights reserved.
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