LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
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3.6.5 GSM PAM(U1001:TQM7M5012)
The TQM7M5012 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 Ω 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 multilayer laminate substrate and the entire assembly is
encapsulated with plastic overmold.
3.6 6 ALM-1412(U1004:GPS LNA)
The ALM-1412 is an LNA module, with integrated filter, designed for GPS band applications at
1.575GHz. The LNA uses AVAGO Technologies’ proprietary GaAs Enhancement-mode pHEMT
process to achieve high gain with very low noise figure and high linearity Noise figure distribution is
very tightly controlled. A CMOS-compatible shutdown pin is included either for turning the LNA on/off,
or for current adjustment. The integrated filter utilizes an Avago Technologies’ leading edge FBAR
filter for exceptional rejection at Cell/PCS Band frequencies. The ALM-1412 is useable down to 1V
operation. It achieves low noise figure, high gain and linearity even at 1V, making it suitable for use in
critical low-power GPS applications or during low-battery situations.
[Figure 1.9] GSM PAM Schematic
MODE
LOW
GSM_PA_BAND
DCS/PCS
HIGH
9dB
GSM
5dB
100
R1014
R1015
100
15p
C1037
30
R1010
2.7nH
L1012
4.7u
C1036
8.2p
C1045
15p
C1044
R1005
2.2K
VBATT
C1040
39p
180
R1011
180
R1012
33p
C1046
C1039
1000p
C1047
DNI
11
DCS_PCS_OUT
GND1
7
12
GND2
GSM_IN
8
9
GSM_OUT
6
NC1
NC2
10
3
TX_EN
4
VBATT
VRAMP
5
TQM7M5012
U1001
BAND_SELECT
2
1
DCS_PCS_IN
L1011
12nH
R1013
62
TX_DCS_PCS
TX_GSM
GSM_PA_EN
GSM_PA_BAND
GSM_PA_RAMP