CCS Technical Documentation
System Module
RH-41
Issue 2 09/2003
Nokia Corporation Confidential
Page 21
Technical Information
ESD protection is made up by (1) spark caps, (2) a buried capacitor (Z152 and Z154-157),
and (3)
±
8kV inside the UEM. The RF and BB noises are prevented by inductors.
PPH-1 Handsfree
Introduction
The PPH-1 handsfree device
• provides the charging and handsfree functionality,
• has a built-in speaker, and
• uses a phone microphone, but also has a connector for the HFM-8 optional external
microphone (using HFM-8 mutes phone microphone).
Interface
A 4-wire interface is implemented with 2.5 mm diameter round plug/jack which is other-
wise like a so-called standard stereo plug, but the innermost contact is split into two.
Figure 8: 4-wire, fully differential headset connector pin layout
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 RH-41
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.
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
