Charger If; Introduction; Interface - Nokia NKC-1X Series Technical Documentation Manual

CCS Technical Documentation
Figure 8: 4-wire, fully differential headset connector pin layout
2 . X E A R N
4 . X E A R P
5 . H E A D IN T
3 . X M IC P
1 . X M IC N

Charger IF

Introduction

The charger connection is implemented through the system connector. The system con-
nector supports charging with both plug chargers and desktop stand chargers.
There are three signals for charging. The charger GND pin is used for both desktop and
plug chargers as well as for charger voltage. The PWM control line, which is needed for
3-wire chargers, is connected directly to the GND in the PWB module, so the NKC-1X
engine does not provide any PWM control for chargers. Charging controlling is done
inside the UEM by switching the UEM's internal charger switch on and off.

Interface

The fuse F100 protects the phone from too high currents, for example, when broken or
pirate chargers are used. L100 protects the engine from RF noises, which may occur in
the charging cable. V100 protects the UEM ASIC from reverse polarity charging voltage
and from too high charging voltages. C106 is also used for ESD and EMC protection.
Spark gaps right after the charger plug are used for ESD protection.
Issue 1 02/03
Nokia Corporation
NKC-1X
System Module
Page 23