LG KT520 Service Manual page 82

3.7.5 Control Flow
The access side of the digital baseband controller controls the overall radio system. In both
EDGE/GSM/GPRS and W-CDMA air interface mode, the digital baseband controller controls the radio
system through a three-wire serial bus.
The digital baseband controller also manages PA band control and the antenna switch mechanism in
the front end module. The 26 MHz VCXO clock residing in the GSM/EDGE transceiver is turned on
only when required, the digital baseband controller initiates this.
The EDGE/GSM/GPRS RF system requires control, which is temperature dependent. The
temperature within the RF system is estimated by a voltage measurement performed by the analog
baseband controller. The control flow for the RF system is shown in Figure 3-7-11.
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Only for training and service purposes
Figure 3-7-11. RF Control Flow
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3. TECHNICAL BRIEF
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