User Guide

PAMS Technical Documentation System Module
NSB-5
Issue 1 03/01 Nokia Mobile Phones Ltd. Page 29
and supply power off.
Battery Temperature
The battery temperature is measured with a NTC inside the battery pack. The BTEMP line
inside transceiver has a 100k pullup to VREF. The MCU can calculate the battery temper-
ature by reading the BTEMP line DC–voltage level with a CCONT (N100) A/D–converter.
Figure 11: Battery Temperature
Supply Voltage Regulators
The heart of the power distrubution is the CCONT. It includes all the voltage regulators
and feeds the power to the whole system. The baseband digital parts are powered from
the VBB regulator which provides 2.8V baseband supply. The baseband regulator is active
always when the phone is powered on. The VBB baseband regulator feeds MAD and
memories, COBBA digital parts and the LCD driver in the UI section. There is a separate
regulator for a SIM card. The regulator is selectable between 3V and 5V and controlled by
the SIMPwr line from MAD to CCONT. The COBBA analog parts are powered from a dedi-
cated 2.8V supply VCOBBA. The CCONT also supplies 5V for RF. The CCONT contains a real
time clock function, which is powered from a RTC backup when the main battery is dis-
connected.
The RTC backup is rechargable polyacene battery, which has a capacity of 50uAh (@3V/
2V) The battery is charged from the main battery voltage by the CHAPS when the main
battery voltage is over 3.2V. The charging current is 200uA (nominal).
0.550.05 Vcc
0.850.05 Vcc
Vcc
GND
S
IGOUT
SIMCARDDETX
100k
VREF
TRANSCEIVER
R
T
BATTERY
BTEMP
BGND
BSI
BVOLT
10n
NTC
1k
MAD
BTEMP
CCONT
VibraPWM
10k
2k2
MCUGenIO4