LG KE520 Service Manual page 48

4.1.2.2 Power Amplifier Module (RPF09036B)
Select the RX / TX path and amplifier the power.
C423
C425
C426
Application
GSM850 / GSM900
DCS1800 / PCS1900
NC2
20
NC1
19
GND5
18
GND4
16
GND3
13
GND2
12
GND1
9
VC2
10
VC1
14
LMSP43NA-504TEMP
C421
33p
C423
15p
C425
56p
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
] Part Description
Front End Module Switch Control
C426 : Tx_ON
C428 : BAND_SELECT
C423 : FEMC1
C425 : FEMC2
U402
C428
Mode
GMSK
EDGE
GMSK
EDGE
L400
0.5p
GSM850_900TX
17
GSM1800_1900TX
15
GSM1900RX2
8
GSM1900RX1
7
GSM1800RX2
L401
6
GSM1800RX1 0.5p
5
GSM900RX2
4
GSM900RX1
3
GSM850RX2
2
GSM850RX1
1
C415
C417 100p
FL400
C418
C422
C418 :
FEMC1
C418 :
R404
FEMC2
L405
3.3nH
C429 C430
NA 1.2p
POUT_GSM
13
GND7
14
VLDO
15
VBAT
VBAT1
16
C432 C433 C434
10u
33nF 47n VBAT2
17
GND5
18
POUT_XCS
19
L406
2.2nH
C436 C437
NA 0.5p
<Fig.2> PAM Circuit Diagram
- 49 -
4. TROUBLE SHOOTING
Vtxon
High
High
High
High
C403 2.7nH
C408
22p
C411 2.7nH
C412 3.3nH
C414 3.3nH
A1
PCSLNAI
B1
PCSLNAIB
C2
100p PCSDCSGND
C1
L403
DCSLNAI
D1
10nH
DCSLNAIB
D2
DCSG90GND
E1
G90LNAI
F1
G90LNAIB
E2
10p
G90G85GND
G1
L404
G85LNAI
12nH H1
G85LNAIB
F2
G85GND
G2
10p
GNDLNA_TX1
H2
TXON
E3
GNDDMIXIN
J2
DMIXIN
J1
DMIXINB
120 100ohm
R402 R403
R405
C426
51 68
22p
120 100ohm
R406 R407
C426 : Tx_ON
PIN_GSM
TX_ON
VRAMP
U402
VREG
RPF09036B
BAND_SELECT
PIN_XCS
Vband
High
High
Low
Low
C404
3.9p
C405
0.1u
U401
R2A60167B
C42
0.01
C428
1000p
C428 :
BAND_SELECT
7
C431
6 NA
5
GND6
4
3
2
1
LGE Internal Use Only