Off-Chip Rf Components - LG -P500 Service Manual

3. TECHNICAL BRIEF

3.6 OFF-CHIP RF COMPONENTS

3.6.1. UMTS PAM
3.6.1.1 W2100,W900 (U1003, SKY77195)
The SKY77195 Power Amplifier Module (PAM) is a fully matched, 14-pad, surface mount module
developed for Wideband Code Division Multiple Access (WCDMA) applications. This small and efficient
module packs full WCDMA Band I and Band VIII coverage into a single compact package. The
SKY77195 meets the stringent spectral linearity requirements of WCDMA transmission, with high
power added efficiency for power output to 27.5 dBm (Band I) and 28 dBm (Band VIII). The SKY77195
meets the stringent spectral linearity requirements of High Speed Downlink Packet Access (HSDPA)
data transmission with high power added efficiency. A directional coupler is integrated into the
module thus eliminating the need for any external coupler.
The single Gallium Arsenide (GaAs) Microwave Monolithic Integrated Circuit (MMIC) contains all active
circuitry in the module. The MMIC contains on-board bias circuitry, as well as input and interstage
matching circuits. Output match into a 50-ohm load is realized off-chip within the module package to
optimize efficiency and power performance.
The SKY77195 PAM is manufactured with Skyworks' InGaP GaAs Heterojunction Bipolar Transistor
(HBT) BiFET process that provides for all positive voltage DC supply operation while maintaining high
efficiency and good linearity. No VREF voltage is required. Power down is accomplished by setting the
voltage on VENABLE to zero volts. No external supply side switch is needed as typical "off" leakage is
a few microamperes with full primary voltage supplied from the battery.
LGE Internal Use Only
SKY77195 (W2100,W900)
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