LG KF700Q Service Manual page 28

3.5.5 GSM PAM (U102:TQMTM5012)
The TQMTM5012 Power Amplifier Module (PAM) is designed in a compact form factor for quad-band
cellular handsets comprising GSM850/900, DCS1800, PCS1900, and supports Class 12 General
Packet Radio Service (GPRS) multi-slot operation.
The module consists of a GSM850/900 PA block and a DCS1800/PCS1900 PA block, impedance
matching circuitry for 50 ߟ input and output impedances, and a Power Amplifier Control (PAC) block.
A custom CMOS integrated circuit provides the internal PAC function and interface circuitry. Two
separate Hetero-junction Bipolar Transistor (HBT) PA blocks are fabricated onto InGaP/GaAs die; one
supports the GSM850/900 bands, the other supports the DCS1800 and PCS1900 bands. Both PA
blocks share common power supply pins to distribute current. The GaAs die, the silicon die, and the
passive components are mounted on a multi-layer laminate substrate and the entire assembly is
encapsulated with plastic overmold.
+VPWR +VPWR
C157 C157
C156 C156 15p 15p
L112 L112
NA NA
C159 C159 15p 15p C160 C160
L113 L113
6.8nH 6.8nH
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
C152 C152 C153 C153 C154 C154
4.7u 4.7u 15p 15p 1000p 1000p
1.5nH 1.5nH
U102 U102
TQM7M5012 TQM7M5012
BAND_SELECT BAND_SELECT
9
GSM_OUT GSM_OUT
DCS_PCS_IN DCS_PCS_IN
39p 39p
11 11
DCS_PCS_OUT DCS_PCS_OUT
GSM_IN GSM_IN
7
GND1 GND1 TX_EN TX_EN
12 12
GND2 GND2
VBATT VBATT
6
NC1 NC1
10 10
NC2 NC2 VRAMP VRAMP
[Fig. 3.7] GSM PAM Schematic
- 29 -
3. TECHNICAL BRIEF
FL102 FL102
LMSM32AA-533 LMSM32AA-533
5 1
RFOUT RFOUT RFIN RFIN
7
VC VC
2
1
8
3
4
R113 R113
5
2.2K 2.2K
C164 C164
39p 39p
TX_GSM TX_GSM
R111 R111
GSM_SAW_SW_MODE GSM_SAW_SW_MODE
100ohm 100ohm
C155 C155
100p 100p
GSM_PA_BAND GSM_PA_BAND
TX_DCS_PCS TX_DCS_PCS
GSM_PA_EN GSM_PA_EN
GSM_PA_RAMP GSM_PA_RAMP
C165 C165 C166 C166
DNI DNI DNI DNI
LGE Internal Use Only