User Guide

CCS Technical Documentation System Module and User Interface
Company confidential RH-23
Issue 1 02/2004 Nokia Corporation. Page 41
DC characteristics
Regulators
The transceiver baseband section has a multi function analog ASIC, UEM, which contains
six pieces of 2.78 V linear regulators and a 4.8 V switching regulator. All the regulators
can be controlled individually by the 2.78 V logic directly or through a control register.
Normally, direct control is needed because of switching speed requirement: the regula-
tors are used to enable the RF-functions, which means that the controls must be fast
enough.
The use of the regulators can be seen in the power distribution diagram, which is pre-
sented in Figure 22, “Power distribution diagram”
The seven regulators are named VR1 to VR7. VrefRF01 and VrefRF02 are used as the ref-
erence voltages for the Helgo, VrefRF01 (1.35V) for the bias reference and VrefRF02
(1.35V) for the RX ADC (analog-to-digital converter) reference.
The regulators (except for VR7) are connected to the Helgo. Different modes of operation
can be selected inside the Helgo according to the control information coming through
the RFBus.
Table 37: List of the needed supply voltages
Voltage source Load
VR1 PLL charge pump (4.8 V)
VR2 TX modulators, VPECTRL3s (ALC),driver
VR3 VCTCXO, synthesizer digital parts
VR4 Helgo pre-amps, mixers, DtoS
VR5 dividers, LO-buffers, prescaler
VR6 LNAs, Helgo baseband (Vdd_bb)
VR7 VCO
VrefRF01 reference voltage for Helgo
VrefRF02 reference voltage for Helgo
Vbatt PA