SKY77529 Datasheet, PDF (1/2 Pages) Skyworks Solutions Inc. – Tx Front-End Module for Quad-Band GSM / EDGE

PRODUCT SUMMARY
SKY77529 Tx Front-End Module for Quad-Band GSM / EDGE
Applications
• Quad-band cellular
handsets:
GMSK Modulation:
- Class 4 GSM850/900
- Class 1 DCS1800/
PCS1900
- Class 12 GPRS multi-slot
operation
EDGE modulation:
- Class E2 GSM850/900
- Class E2 DCS1800/
PCS1900
Features
• WCDMA pass-through
- 4 linear ports
• TRP-compliant design
• SPI bus support
• Low loss PHEMT RF
antenna switch
• Detector output: linear V/V
• Closed loop GMSK mode
power control
• Small, low profile package
- 7.5 x 7.0 x 0.9 mm MAX.
- 26-pad configuration
• Gold-plated, lead-free
contacts
• Low VRAMP current
Description
The SKY77529 Tx Front End Module (FEM) is designed in a compact form factor for quad-band
cellular handsets comprising GSM850/900, DCS1800, PCS1900, supporting GMSK and linear EDGE
modulation. Class 12 General Packet Radio Service (GPRS) multi-slot operation is also supported.
The module consists of a GSM850/900 PA block and a DCS1800/PCS1900 PA block, a printed
directional coupler for each block impedance-matching circuitry for 50 Ω input and output
impedances, a multifunction power amplifier control (MFC) block, low pass harmonic rejection filters,
and an SP8T Antenna T/R switch. The T/R switch incorporates four linear ports to allow WCDMA
parallel operation.
Two separate Heterojunction Bipolar Transistor (HBT) PA blocks are fabricated onto an InGaP die; one
supports the GSM850/900 bands, the other supports the DCS1800 and PCS1900 bands. The InGaP PA
die, the silicon MFC die, PHEMT switch die, and the passive components are mounted on a multi-layer
laminate substrate. The assembly is encapsulated with plastic overmold.
The FEM incorporates full support for a Serial Peripheral Interface (SPI) bus function. The SPI
controller shall accept SPI telegrams with data fields that support PA and switchplexer-related
functions. All FEM operating modes and switch states shall be determined by the SPI telegram.
The Multi-function Control (MFC) provides for interoperation with a specified transceiver that will
establish a closed loop power control mechanism. The external circuit uses the Linear Detector output
to set a fixed bias point for 8PSK (EDGE) mode and a variable bias point for GMSK (GSM) mode. The
power control loop together with the MFC will reduce sensitivity to antenna load, input drive,
temperature, power supply, and process variation. The combined circuit configures the PA for fixed
gain in 8PSK mode while providing the ability to optimize the PA bias at different power levels to
maximize efficiency.
Figure 1. SKY77529 Functional Block Diagram
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
201051B • Skyworks Proprietary and Confidential Information • Products and Product Information are Subject to Change Without Notice. • May 20,2009
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