LG -E405 Service Manual page 34

2mm
VBAT
TP1
GSM_PA_RAMP
Module Control and Antenna Switch Logic
ANT_SEL 3 ANT_SEL 2
0
0
0
0
0
1
1
LGE Internal Use Only
ANT_SEL2
ANT_SEL1
C1038
C1039
ANT_SEL0
22u
47p
ANT_SEL3
R1002
2.2K
C1047
39p
GSM_TX
GSM850(824-849MHz)
GSM900(880-915MHz)
DCS_PCS_TX
DCS(1710-1785 MHz)
PCS(1850-1910 MHz)
Schematic of the Antenna Switch Block
ANT_SEL 1
0 0
1 0
0 1
0 1
0 0
0 1
0 1
GND TRX2
7
VBATT TRX1
18
GPCTRL2
RX2
17
GPCTRL1 RX1
19
GPCTRL0
GND7
U1001
20
TX_EN GND4
21
VRAMP GND3
22
PGND1 GND8
23
PGND2 GND1
24
GND2
8
C1049
56p
R1006
C1055
75
22p
11dB
R1011
47
7dB
ANT_SEL 0
0
0
0
1
1
0
1
- 34 - Copyright © 2012 LG Electronics. Inc. All right reserved.
4. TROUBLE SHOOTING
WCDMA_900_RTX
13
WCDMA_2100_RTX
12
11
10
16
6
9
2
1
Tx Module Mode
Standby
Rx1
Rx2
TRX1
TRX2
Low Band GMSK
High Band GMSK
Only for training and service purposes