Supply voltage regulators

The heart of the power distribution is the CCONT. It includes all the voltage regulators and feeds the power to the whole system. The baseband digital parts are powered from the VBB regulator which provides 2.8V baseband supply. The baseband regulator is active always when the phone is powered on. The VBB baseband regulator feeds MAD2WD1 and memories, COBBA digital parts and the LCD driver in the UI section. There is a separate regulator for the SIM card. The regulator is selectable between 3V and 5V and controlled by the SIMPwr line from MAD2WD1 to CCONT. The COBBA analog parts are powered from a dedicated 2.8V supply VCOBBA. The CCONT supplies also 5V for RF.

Table 12: Regulator Activity - Different Operating Modes

Operating mode

Vref

RF REG

VCOBBA

VCORE

VBB

VSIM

SIMIF

Power off

Off

Off

Off

Off

Off

Off

Pull down

Power on

On

On/Off

On

On

On

On

On/Off

Reset

On

VR1 On VR6 On

On

On

On

Off

Pull down

Sleep

On

On/Off

Off

Off

On

On

On/Off

CCONT includes also five additional 2.8V regulators providing power to the RF section. These regulators are controlled by SW via the serial Bus GENSIO(1:0) from the MAD2WD1.

CCONT generates also a 1.5 V reference voltage VREF to COBBA. The VREF voltage is also used as a reference to some of the CCONT A/D converters.

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