User Guide

NPM-6/6X
System Module and User Interface CCS Technical Documentation
Page 40 Nokia Corporation. Issue 2 06/03
DC characteristics
Regulators
The transceiver baseband section has a multi function analog ASIC, UEM, which contains
among other functions six pieces of 2.78 V linear regulators and a 4.8 V switching regu-
lator. 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 regulators are used to enable the RF-functions which means that the
controls must be fast enough.
The seven regulators are named VR1 to VR7. VrefRF01 is used as the reference voltages
for the Helga, VrefRF01 (1.35V) for the bias reference and for the RX ADC (analog-to-
digital converter) reference.
The regulators (except for VR7) are connected to the Helga. Different modes of operation
can be selected inside the Helga according to the control information coming through
the RFBus.
List of the needed supply voltages
Volt. source Load
VR1 PLL charge pump (4.8 V)
VR2 TX modulators, ALCs, driver
VR3 VCTCXO, synthesizer digital parts
VR4 Helga pre-amps, mixers, DtoS
VR5 dividers, LO-buffers, prescaler
VR6 LNAs, Helga baseband (Vdd_bb)
VR7 VCO
VrefRF01 ref. voltage for Helga
Vbatt PA