Nokia 3105 Servicehandbuch
RH-48
System Module
CCS Technical Documentation
Page 4
©
2003 Nokia Corporation Confidential
Issue 1 11/2003
Figure 1: Baseband module diagram
UEM
UEM Introduction
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.
addition to energy management, it performs all the baseband mixed-signal functions.
Most of UEM pins have 2kV ESD protection. Those signals that 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.
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
UEM has six regulators for baseband power supplies and seven regulators for RF power
supplies. RH-48 has a DC/DC connector to provide power to the UPP VCORE.
supplies. RH-48 has a DC/DC connector to provide power to the UPP VCORE.
Bypass capacitor (1uF) is required for each regulator output to ensure stability.
Reference voltages for regulators require external 1uF capacitors. Vref25RF is reference
voltage for VR2 regulator; Vref25BB is reference voltage for VANA, VFLASH1, VFLASH2,
VR1 regulators; Vref278 is reference voltage for VR3, VR4, VR5, VR6, VR7 regulators;
VrefRF01 is reference voltage for VIO, VCORE, VSIM regulators, and for RF.
voltage for VR2 regulator; Vref25BB is reference voltage for VANA, VFLASH1, VFLASH2,
VR1 regulators; Vref278 is reference voltage for VR3, VR4, VR5, VR6, VR7 regulators;
VrefRF01 is reference voltage for VIO, VCORE, VSIM regulators, and for RF.