LG FM300 Service Manual page 21

3. TECHNICAL BRIEF
3. TECHNICAL BRIEF
3.2.3 LTE PAM (SKY77704-8, U101, U102)
The SKY77704-8 Power Amplifier Module (PAM) is a fully matched, surface mount module developed for LTE /
EUTRAN applications. This small and efficient module packs full coverage of LTE Band IIX into a single
compact package.
The SKY77704-8 meets the stringent spectral linearity requirements of LTE modulation with QPSK / 16QAM
modulations from 1.4 MHz to 20 MHz bandwidth and full or partial resource block allocations with high power
added efficiency.
The single Gallium Arsenide (GaAs) Microwave Monolithic Integrated Circuit (MMIC) contains all active
circuitry in the module, including the PA, input, and interstage matching. Output match is realized offchip i i i h d l i l di h PA i d i hi O h i li d ff hi
within the module package to optimize efficiency and power performance into a 50 Ω load.
The SKY77704-8 is manufactured with Skyworks' BiFET process which provides for all positive voltage DC
supply operation while maintaining high efficiency and good linearity. Primary bias is supplied via the
VCC1 and VCC2 pads directly from battery output in the 3.2 to 4.2 volt range. Power-down is accomplished by
setting a logic low level on the VEN pad. No external supply side switch is needed as typical "off" leakage is a
few microamperes with full primary voltage supplied from the battery.
The VMODE0 and VMODE1 pads are sed to s itch bet een high medi m and lo po er modes to red ce The VMODE0 and VMODE1 pads are used to switch between high, medium and low power modes to reduce
current consumption and gain in the back-off conditions.
Figure 3.10 PAM Module
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