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LGE Internal Use Only
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
LGE Internal Use Only
Internal Block Diagram
3.13 Front End Module control & Power Amplifier Module
(SKY77531, U502)
Figure. 3-13-2 SKY77318 FUNCTIONAL BLOCK DIAGRAM
General Description
The SKY77531 is a transmit and receive front-end module (FEM) with Integrated Power Amplifier Control
(iPAC™) for quad-band cellular handsets comprising GSM850/900 and DCS1800/PCS1900 operation.
Designed in a low profile, compact form factor, the SKY77531 offers a complete Transmit VCO-to-Antenna
and Antenna-to-Receive SAW filter solution. The FEM also supports Class 12 General Packet Radio Service
(GPRS) multi-slot operation.
The band select pads, BS1 and BS2, select GSM850,GSM900, DCS, and PCS modes of operation. Transmit
enable Tx_EN controls receive or transmitmode of the RF switch (Tx = logic 1).