User Guide

Nokia Customer Care System Module
Company Confidential RH-21
Issue 2 07/2004  2004 Nokia Corporation. Page 7
Baseband Module
The core parts of 3560/3520 BB consists of two ASICs—UEM and UPP—and flash memory.
The following sections describe these parts.
Figure 2: System Block Diagram (simple)
UEM
UEM introduction
The UEM is the Universal Energy Management IC for DCT4 digital handportable phones.
In addition to energy management, it performs all the baseband mixed-signal functions.
Most UEM pins have 2kV ESD protection and those signals which are considered to be
exposed more easily to ESD have 8kV protection inside UEM. Such signals are all audio
signals, headset signals, BSI, Btemp, Fbus, and Mbus signals.
Regulators
The UEM has six regulators for BB power supplies and seven regulators for RF power sup-
plies. The VR1 regulator has two outputs (VR1a and VR1b). In addition, there are two
current generators (IPA1 and IPA2) for biasing purposes.
A bypass capacitor (1uF) is required for each regulator output to ensure stability.
RFBUS
UEM
UPP
FLASH
Battery
CBUS/
DBUS
BB
Supplies
RF Supplies
UI
DCT4 Janette connector
RF RX/TX
PA Supply
MBus/FBus
External Audio
Charger connection
Safari
19.44MHz
SLEEPCLK
32kHz
Baseband
MEMADDA
M
VIBRA
XEAR
EAR
MIC
DLIGHT
KLIGHT
LM4890