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LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
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* L705i WB2100 band uses WB1900 path in the FEM. So the FEM logic is changed from (1,0,1) to
(0,0,1).
Logic Table of the Front End Module
Switch Mode
CTRL1
CTRL2
CTRL3
GSM850/EGSM TX
1
0
1
PCN/PCS TX
0
1
1
WB850
0
1
1
WB1900
1
0
1
WB2100
0
0
1
GSM850 RX
0
0
0
EGSM RX
1
0
0
PCN RX
1
1
0
PCS RX
0
1
0
All Off
1
1
1
min
typ
max
Power supply voltage
V
DC
2.5
2.75
3.2
V
V
DC
Control voltage high
V
DC
1.4
V
Ctrl 1, Ctrl 2, Ctrl 3
Control voltage low
V
DC
0.4
V
Ctrl 1, Ctrl 2, Ctrl 3
Power supply current max
I
DC
13
50
µ
A
Control current max
I
DC
2
µ
A
Switching Speed
T
3
µ
S
Check Soldering of
ANT_SEL 0,1,2 High Level
1.5V<Voltage<3.0V
Check the Logic
in each mode
Check Vdd
VREG_RF_SMPS
NO
YES
Checking Switch Block power source
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