Nokia 6255 Service Manual

Nokia Customer Care

Baseband Description and Troubleshooting

6255/6255i6256/6256i (RM-19)

Issue 2 05/2005

©2005 Nokia Corporation     Company Confidential

Page 25

The mobile terminal uses a Lithium-Ion cell battery (BL-6C) with a capacity of 1070mAh. 
Reading a resistor inside the battery pack on the BSI line indicates the battery size. An 
NTC resistor close to the SIM connector measures the mobile terminal’s temperature on 
the BTEMP line. Temperature and capacity information are needed for charge control. 
These resistors are connected to the BSI pins on the UEM. The mobile terminal has 
100K

Ώ

 pull-up resistors for these lines so that they can be read by A/D inputs in the 

mobile terminal.

The UEME ASIC controls charging depending on the charger being used and the battery 
size. External components are needed for Electromagnetic Compliance (EMC), reverse 
polarity, and transient protection of the input to the baseband module. The charger 
connection is through the system connector interface. The baseband is designed to 
support DCT3 and higher chargers from an electrical point of view. Both 2- and 3-wire 
type chargers are supported. However, the 3-wire charger is treated as a 2-wire charger.