User Guide

NSB-5
System Module PAMS Technical Documentation
Page 28 Nokia Mobile Phones Ltd. Issue 1 03/01
The performance travel charger (3– wire charger) is controlled with PWM at a frequency
of 32Hz. When the PWM rate is 32Hz CHAPS keeps the power switch continuously in the
ON state.
Battery Identification
Different battery types are identified by a pulldown resistor inside the battery pack. The
BSI line inside transceiver has a 100k pullup to VBB.
The MCU can identify the battery by reading the BSI line DC–voltage level with a CCONT
(N100) A/D–converter.
Figure 10: Battery Identification
The battery identification line is used also for battery removal detection. The BSI line is
connected to a SIMCardDetX line of MAD2 (D300). SIMCardDetX is a threshold detector
with a nominal input switching level 0.85xVcc for a rising edge and 0.55xVcc for a falling
edge. The battery removal detection is used as a trigger to power down the SIM card
before the power is lost. The BSI contact in the battery pack is made 0.7mm shorter than
the supply voltage contacts so that there is a delay between battery removal detection
SWITCH
PWM (1Hz)
SWITCH
PWM (32Hz)
ON
ON ONON OFF OFF
SIMCardDetX
MAD
BSI
CCONT
Vbb
TRANSCEIVER
R
s
BATTERY
BSI
BGND
BTEMP
BVOLT
10k
10n
100k
Vibra Schematic