LG GX500 Service Manual page 123

7. CIRCUIT DIAGRAM
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LGE Internal Use Only
10 9 8
GSM850 / 900_TX
GSM 1800 / 1900_ TX
GSM850 / 900_RX
GSM 1800 / 1900_ RX
SW401
GND402 ANT401
L403 20p C418
2
ANT COMMON ANT
1 100P 17
G3 G4
4 3
100NH
C440
L407
C405 1p C436
2.2n 18n
GSM850 GSM900
C421
C409 C412 C426
3.3p
C407 C423 4.7P 4.7P 3.3p
0.1U 4.7N
FE1
FE2
FE2
33
VBIAS
34
VDDTX1V5
35
LBAND_PAM_IN TX1
36
HBAND_PAM_IN TX2
37
R405 VDDTX2V8
38
VDDMIX2V8
10
C432 39
GND3
0.22U 40
GND4
41
R401
10
C413 C438
220N 0.1U
10 9 8
7 6 5
VC1 (FE1) VC2 (FE2)
H L
L H
L L
L L
FE1
FE2
100P 100P
C439 C424
L404
4.7p
12 1
DCS_PCS_OUT DCS_PCS_IN
C433 10 2
C428 GSM850_900_OUT MODE_SELECT
0.5p 8.2n
13 3
BY_CAP1 BS
U402
L406 9 4
DCS1800 PCS1900 BY_CAP2 TQM7M5005H VBATT
3.9p
14 5
GND1 VRAMP
11
GND2
8 6
GND3 TX_EN
C435 C408 C431 C427 C417 C425 C422 15 7
C410 PGND GSM850_900_IN
2.2P 2.2P 2.7p 2.7p 12n 22n 0.01U 0.01U OK
C414
1u
C430 C416 C411
0.1U 0.1U 0.1U C442
0.1U
VDDRX2V8
20
VDDRX1V5 R402
19
VCO_RC
820
18
VDDVCO2V8
17
EN RF_EN
16
VDDXO2V8
15
FSYS1 26MHZ_MCLK
14
GND1
13
X401
4 3
1 2
26MHz
DSX321SG-26M
RF_CLK
RF_DA
QX
TP401
Q
IX
TP402
I
7 6 5
- 124 -
4 3 2
R407
HBAND_PAM_IN
100P
PA_MODE
S1_PA_BAND
R403
PA_LEVEL
10K
TXON_PA
R404
LBAND_PAM_IN
100P
C441 C415 C429
C420
C437 C434 100P 100P 47P 100P
33u
27P
OK
R406
S1_RF_TEMP
22K
PT401
10K
4 3 2
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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