4.13.3 Checking Mobile SW & FEM
Mobile SW & FEM Circuit Diagram
Checking Points
LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
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Figure 8. Mobile SW & FEM Circuit
Figure 9. Mobile SW & FEM
Table 2. FEM RX Control Logic
VC1 (FE1)
GSM 1800 / 1900_ TX
L
L
L
H
H
VC2 (FE2)
GSM850 / 900_RX
GSM 1800 / 1900_ RX
H
H
LMSP43QA-538(CMOS)
L
GSM850 / 900_TX
C410
0.5p
100nH
L406
C407
DNI
6.8nH
L404
C411
0.5p
ANT
G1
G2
G3
ANT400
WFL-R-SMT10
2V85_VRF
C400
1000p
C406
100p
100ohm
R403
100ohm
R402
RF-800
SW400
ANT
G1
G2
RF
15
GSM1800_RX1
5
6
GSM1800_RX2
GSM1900_RX1
7
8
GSM1900_RX2
17
GSM850_900_TX
GSM850_RX1
1
2
GSM850_RX2
GSM900_RX1
3
4
GSM900_RX2
23
NC1
24
NC2
19
VC1
VC2
20
21
VDD
11
ANT
GND1
9
GND2
10
12
GND3
GND4
13
GND5
14
GND6
16
18
GND7
22
GND8
GSM1800_1900_TX
LMSP43QA-538
FL400
100p
C402
C401
100p
FE1
FE2
SW401
TP3_R402 (FE1)
FL401
TP1
TP2
TP4_R403 (FE2)
TP5 ~ 8
EGSM/GSM850
DCS/PCS
FE1
ON OFF
FE2 OFF
OFF
TP1
TP4
TP3
TP1
TP9