3. TECHNICAL BRIEF
- 39 -
LGE Internal Use Only
Copyright © 01 LG Electronics. Inc. All right reserved.
Only for training and service purposes
- 39 -
LGE Internal Use Only
Copyright © 011 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
3.5.2.3 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
amplifiers is achieved by the implemented bias DAC.
Fi
3 5 4 PA AND FEM CONTROL BLOCK DIAGRAM
Figure. 3.5.4 PA AND FEM CONTROL BLOCK DIAGRAM
ͽͶ͑ͺΟΥΖΣΟΒΝ͑ΆΤΖ͑ΟΝΪ
[WVX[^
biasdac_data
to
baseband
as rf_fe4_0
INIT_PAFEM_A
PABIASFE 3_SEL
BIAS
DAC
PAMP
DAC
CHANNEL_BSW[1]
INIT_PAFEM_A.PABS_INV
ramping signal
GSM 850/900
GSM 1800/1900
TX2
TX1
RFIN
HB
RFIN
LB
RFOUT
HB
RFOUT
LB
to ASM / FEM
to ASM / FEM
GMSK PA
VBIAS
BS
TX_EN
VP
AMP
VPAMP
PABS
PAEN
PABIAS/FE3
FE2
FE1
FE2
FE1
FE3
FE4
PAEN