Nokia 5110 Manual Do Serviço

Página de 78
PAMS
Technical Documentation
NSE–1
System Module
Page 3 – 17
Original  03/98
Functional Description
Power Distribution
In normal operation the baseband is powered from the phone‘s battery.
The battery consists of one Lithium–Ion cell. There is also a possibility to
use batteries consisting of three Nickel Metal Hydride cells. An external
charger can be used for recharging the battery and supplying power to
the phone. The charger can be either a standard charger that can deliver
around 400 mA or so called performance charger, which can deliver sup-
ply current up to 850 mA.
The baseband contains components that control power distribution to
whole phone excluding those parts that use continuous battery supply.
The battery feeds power directly to three parts of the system: CCONT,
power amplifier, and UI (buzzer and display and keyboard lights). Figure
below shows a block diagram of the power distribution.
The power management circuit CHAPS provides protection agains over-
voltages, charger failures and pirate chargers etc. that would otherwise
cause damage to the phone.
CCONT
SIM
+
BOTTOM CONNECTOR
CHAPS
COBBA
BATTERY
PA SUPPLY
RF SUPPLIES
VBB
BASEBAND
VBAT
VCOBBA
VSIM
VBB
CNTVR
PWM
VBAT
PWRONX
PURX
VIN
UI
BACKUP
RTC
MEMORIES
MAD
LIM
VBB