User Guide

PAMS
Technical Documentation
NSB–1
System Module
Page 3 – 17
Original 06/98
Power Distribution
In normal operation the baseband is powered from the phone‘s battery.
The battery consists of one Lithium–cell. There is also a possibility to use
batteries consisting of three Nickel–cells. An external charger can be
used for recharging the battery and supplying power to the phone. The
charger can be either so called fast charger, which can deliver supply cur-
rent up to 850 mA or a standard charger that can deliver around 300 mA.
The baseband contains components that control power distribution to
whole phone excluding the power amplifier, which have a continuous
power rail direct from the battery. The battery feeds power directly to
three parts of the system: CCONT, power amplifier, and UI (buzzer and
display and keyboard lights).
The power management circuitry provides protection against overvol-
tages, charger failures and pirate chargers etc. that would otherwise
cause damage to the phone. The circuitry is implemented in the begin-
ning with discrete components, but it will be partly or fully integrated on
later phase.
CCONT
SIM
+
CONNECTOR
POWER
COBBA
BATTERY
PA SUPPLY
RF SUPPLIES
VBB
BASEBAND
VBAT
VCOBBA
VSIM
VBB
CNTVR
PWM
VBAT
PWRONX
PURX
VIN
UI
MGMT
BACKUP
RTC
MEMORIES
MAD
V2V
The heart of the power distribution is the CCONT. It includes all the volt-
age regulators and feeds the power to the whole system. The whole
baseband is powered from the same regulator which provides 2.8V base-
band supply VBB. The baseband regulator is active always when the
phone is powered on. The baseband regulator feeds MAD and memories,
COBBA digital parts and the LCD driver in the UI section. There is a sep-
arate regulator for a SIM card.