LG GT540 Service Manual page 89

4. Trouble Shooting
4.5.1 GSM Quad-Band PAM (U100: SKY77544)
The module consists of a GSM850/900 PA and DCS1800/PCS1900 PA block, impedance-matching circuitry for 50 Ω input and
output impedances, Tx harmonic filtering, high linearity-low insertion loss switches, and a CMOS Power Amplifier Control (PAC)
block. A custom silicon integrated circuit contains decoder circuitry to control the RF switch while providing a low current
external control interface. An integrated temperature sensor provides an analog voltage based on the temperature of the
module.
Applications
• Quad-band cellular handsets encompassing -Class 4 GSM850/900 -Class 1 DCS1800 PCS1900 -Class 12 GPRS
multi-slot operation -EDGE polar modulation -Triple band WCDMA antenna
switch support
Features
Small outline: 6 mm x 6 mm
Very low profile: 0.9 mm
28-pad package
Low input power range -0 to 6 dBm
High efficiency -GSM850 41% -GSM900 41% -DCS 38% -PCS 38%
Tx-VCO-to-antenna and antenna-to-Rx-SAW filter RF interface
Tx harmonics below -38 dBm
Wideband envelope control path
Input/Output matching 50 Ω internal
Low APC current 20 μA
High impedance control inputs 15 μA, typical
Integrated module temperature sensor
ANT101 ANT102
L139
2.2n
C160
100p
GND
R117
GSM_PA_RAMP
2.2K
0603
DCS_PCS_TX
DCS(1710-1785 MHz)
PCS(1850-1910 MHz)
GSM_TX
GSM850(824-849MHz)
GSM900(880-915MHz)
2mm
VBAT
C113
10u
LGE Internal Use Only
R112
6.8p C128
100p
C157
R113
DNI
DNI
C149
39p
R104
51
7dB
R110
82
11dB
0603 0603
C153 1n
C179
C155 1n
47p
C162 1n
C164 1n
ANT_SEL3
ANT_SEL2
ANT_SEL0
ANT_SEL1
SW100
TP1
G1
A
C
G2
C159 33p
L107
100n
PGND16
PGND15
PGND14
1
DCS_PCS_IN PGND13
2
GND1
3
GSM_IN
4
VAPC
5
VBATT GND5
6
BS2 GND4
U100
7
BS1 GND3
8
_TXEN GND2
ANT
WCDMA3
29
PGND1 WCDMA2
30
PGND2 WCDMA1
31
PGND3
32
PGND4
33
PGND5
34
PGND6 PGND12
PGND11
PGND10
- 90 - Copyright © 2010 LG Electronics. Inc. All right reserved.
WCDMA_1900_RTX
WCDMA_900_RTX
WCDMA_2100_RTX
44
43
42
41
22
21
20
19
18
17
16
15
40
39
38
L110
5.6n
Only for training and service purposes
2 3
FL10
G1 O1
1
IN
G2 O2
5 4
881.5MHz
2 3
FL10
G1 O1
1
IN
G2 O2
C119 100p
5 4
942.5MHz
L112
DNI
2 3
FL10
C117 100p
G1 O1
1
IN
G2 O2
5 4
L111
DNI
1842.5MHz
56p
2 3
FL10
G1 O1
1
IN
G2 O2
5 4
1960MHz