LG KE590 Service Manual page 44

4.1.2.2 Power Amplifier Module (RPF09036B)
Select the RX / TX path and amplifier the power.
U404
C418
U404
C421
C423
Application
GSM850 / GSM900
DCS1800 / PCS1900
GND13
26
GND12
25
GND11
24
GND10
23
GND9
22
GND8
21
GND7
20
GND6
9
GND5
8
GND4
7
GND3
6
GND2
4
GND1
2
VC_EGSMGSM850TX
11
VC_DCSPCSTX
3
C418
56p
C420
15p
C424
1p
VBAT
C431
0.5p
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
] Part Description
Front End Module Switch Control
C421 : Tx_ON
C420
C423 : BAND_SELECT
C418 : Vc_EGSMGSM850_Tx
C420 : Vc_DCSPCS_Tx
Mode
GMSK
EDGE
GMSK
EDGE
EGSMGSM850TX
10
DCSPCSTX
5
PCSRX2
19
FL401 PCSRX1
18
HWXR693
SFAY00009801 DCSRX2
17
DCSRX1
16
EGSMRX2
15
EGSMRX1
14
GSM850RX2
13
GSM850RX1
12
C418: EGSMGSM850_TX
120
R407
R410
8dB ATT
51
C420: DCSPCS_TX
120
R412
R415 3.3nH
C425
NA
POUT_GSM
13
GND7
14
VLDO
15
VBAT1
16
C427 C428 C429 C440
10u
0.1u 47n 1u VBAT2
17
GND5
18
POUT_XCS
19
R416 1nH
C432
NA
<Fig.2> PAFEM Circuit Diagram
4. TROUBLE SHOOTING
Vtxon
High
High
High
High
p
A1
PCSLNAI
B1
PCSLNAIB
C2
PCSDCSGND
C1
DCSLNAI
D1
DCSLNAIB
D2
DCSG90GND
E1
G90LNAI
F1
G90LNAIB
E2
R2A60167
G90G85GND
G1
G85LNAI
H1
G85LNAIB
F2
G85GND
G2
GNDLNA_TX1
H2
TXON
E3
GNDDMIXIN
J2
DMIXIN
J1
DMIXINB
120
R408
R411
8dB ATT
C421
51
22p
120
C421: Tx_ON
R413
C423
1000p
(NC)
PIN_GSM
7
TX_ON
6
VRAMP
5
GND6
U404
4
VREG
RPF09036B
3
SMPY0014901
BAND_SELECT
2
PIN_XCS
1
- 45 -
Vband
High
High
Low
Low
0.1u
U403
EUSY03168
(NC) (NC)
C
0.
C423: BAND_SELECT
C426
NA
LGE Internal Use Only