User Guide

NSM–3
System Module
PAMS Technical Documentation
Page 17
Issue 1 12/1999
 Nokia Mobile Phones Ltd.
0.550.05 Vcc
0.850.05 Vcc
Vcc
GND
S
IGOUT
SIMCARDDETX
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 temperature by reading the BTEMP line DC–
voltage level with a CCONT (N100) A/D–converter.
Pin Name Min Typ Max Unit Notes
3 BTEMP
0 1.4 V Battery temperature indication
100k pullup resistor to VREF in phone
Battery package has NTC pull down resis-
tor:
47k +/–5%@+25C , B=4050+/–3%
2.1
5 10
3
20
V
ms
Phone power up by battery (input)
Power up pulse width
1.9
90
100
2.8
200
V
ms
Battery power up by phone (output)
Power up pulse width
–5 5 % 100k pullup resistor tolerance
100k
VREF
TRANSCEIVER
R
T
BATTERY
BTEMP
BGND
BSI
VBATT
NTC
BTEMP
CCONT
10k