LG KF750 Service Manual page 81

3. TECHNICAL BRIEF
A. Front End Part
SKY77519 TX-RX Front End Module (FEM) offers a complete transmit VCO-to-Antenna and Antenna-
to-receive SAW filter solution in a low profile (1.2 mm), compact form factor for handsets comprising
GSM850/900, DCS1800, and PCS1900 operation. The FEM also supports Class 12 General Packet
Radio Service (GPRS) multi-slot operation, Polar EDGE modulation, and provides single UMTS band
(band 1 or band 2) antenna switch-through via a dedicated UMTS port.
T X _ D C S P C S
A N T S W 0
A N T S W 1
A N T S W 2
V A P C
T X _ E G S M
LGE Internal Use Only
Figure 3-7-9. SKY77519 Functional Block Diagram
G N D 6
1 5
G N D 7
1 6
G N D 8
1 7
C 1 0 4 G N D 9
1 8
2 2 p G N D 1
1 9
G N D 1
2 0
G N D 1
2 2
G N D 1
2 4
D C S _
2 1
G S M _
2 3
V A P C
2 5
C 1 0 5 C 1 0 6
2 2 p 2 2 p
V B A T
2 6
B S 2
2 7
B S 1
2 8
Figure 3-7-10. Front End part schematic
C 1 0 0 C
2 2 p 1
P G N D
2 9
G N D 5
1 4
G N D 4
1 3
0 G N D 3
1 2
1 G N D 2
1 1
2 G N D 1
9
3
W C D M A 1
1 0
P C S _ N I R X 1
7
R X 2
6
N I R X 3
5
R X 4
4
R S V D
3
T M O D E
2
T X E N
1
C 1 0 7 2 2 p
A N T
8
S K Y 7 7 5 1 9 U 1 0 0
Copyright © 2008 LG Electronics. Inc. All right reserved.
- 82 -
V B A T
1 0 1 C 1 0 2 C 1 0 3
0 n 1 0 u 1 0 u
W R F _ B A N D _ 1
R X 8 5 0
R X 9 0 0
R X 1 9 0 0
R X 1 8 0 0
D I N
C 1 0 8
S W 1 0 0
K M S 5 - 1 8
Only for training and service purposes