LG GX300 Service Manual page 40

3.6.2.3 Front-end/PA Control Interface
Two outputs (FE1, FE2) for direct control of antenna switch modules enable to select RX- and TX-mode
as well as low- and high-band operation.
An extra band select signal PABS for the power amplifier is used, to support discrete PA and switching
modules. Time accurate power dissipation of the PA is achieved by the control signal PAEN.
A minor set of power amplifiers require a bias voltage to enhance power efficiency. Support of this
power amplifiers is achieved by the implemented bias DAC.
Figure. 3.6.4 PA AND FEM CONTROL BLOCK DIAGRAM
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3. TECHNICAL BRIEF
3. TECHNICAL BRIEF
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