User Guide

NSB-5
System Module PAMS Technical Documentation
Page 20 Nokia Mobile Phones Ltd. Issue 1 03/01
Power Distribution
In normal operation the baseband is powered from the phone‘s battery. The battery con-
sists of one Lithium–Ion cell. There is also a possibility to use batteries consisting of
three Nickel Metal Hydride cells or one solid state cell. 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 current up to 1600 mA or a standard
charger that can deliver approx 300 mA.
The CCONT provides voltage to the circuitry excluding the RF PA, LCD, and IrDa, which
are supplied via a continuous power rail direct from the battery. The RF PA module has a
cutoff voltage of 3.1V. The battery(see note) feeds power directly to several parts of the
system: CCONT, PA, and UI circuitry (display lights, buzzer). The four dedicated control
lines, RxPwr, TxPwr, SIMCardPwr, and SynthPwr from MAD2 to CCONT have changed to a
serial control signal between MAD2WD1 and CCONT. Figure 8 shows a simplified block
diagram of the power distribution.
Note : In battery terms there is VBATT and VB, the difference is a filter (coil and capacitors).
The power management circuitry provides protection against overvoltages, charger fail-
ures, and pirate chargers, etc., that could cause damage to the phone.
Figure 8: Baseband power distribution
The heart of the power distribution is the CCONT. It includes all the voltage regulators
and feeds the power to most of the system. The whole baseband is powered from the
same regulator which provides 2.8V baseband supply VBB. The baseband regulator is
active always when the phone is powered on. The core baseband regulator feeds,
amongst others, MAD2WD1 and memories, COBBA_GJP digital parts and the LCD driver
in the UI section. COBBA_GJP analog parts are powered from a dedicated 2.8V supply
CCONT
SIM
+
CONNECTOR
POWER
COBBA_GJP
BATTERY
PA SUPPLY
RF SUPPLIES
VBB
BASEBAND
VBAT
VCOBBA
VSIM
VBB
CNTVR
PWM
VBAT
PWRONX
PURX
VIN
LCD
MODULE
MGMT
BACKUP
RTC
MEMORIES
MAD2WD1
core voltage
sram