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able and controlled by register writings by the MCU. VCORE supplies the core of the UPP
and can be adjusted on the fly by the MCU if DSP capacity is inadequate. Higher VCORE
supply (1.8 V) results in faster core operations in the UPP.
The regulators VANA, VFLASH1 and VIO are solely controlled by the UEM and cannot be
en-/disabled by MCU writings. Furthermore, VFLASH1 and VIO are both ON, though in
low quiescent mode when the phone is in sleep mode. An output current of 500 µA can
be drawn from the VIO regulator and 1.5 mA from the VFLASH1 regulator. VIO supplies
the UPP, FLASH and LCD, VFLASH1 supplies LCD, IRDA and the Bluetooth module. VANA
is supplying analogue parts internally in the UEM as well as the baseband audio circuitry
and pull-up resistors on the input of the UEM slow AD converters.
The regulators VR1A, VR1B, VR2 – VR7 and IPA1 – IPA4 are all controlled by the DSP via
the DBus. VR3 – VR7 are controlled by the UEM as well and are disabled in sleep regard-
less of DSP writings.
VBAT is furthermore distributed, unregulated, to the RF power-amplifier and the BT102
Bluetooth module as well as filters in the baseband module.
The CHACON module is not used on TF4.
Issue 2.0 Mar/2005
Figure 4: Baseband power distribution
Copyright © 2005 Nokia Corporation.
TF4 Technical Information