LG TracFone LG840G Service Manual page 22

3.2.3 Power Amplifier Module
The SKY77196 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 II and
Band V coverage into a single compact package. The SKY77196 meets the stringent spectral linearity requirements of
WCDMA transmission, with high power added efficiency for power output to 28.5 dBm (Band II) and 28 dBm (Band V).
The SKY77196 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 SKY77196 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.
VMODE0 (2)
VEN_BAND_II (6)
VEN_BAND_V (5)
VMODE1 (3)
IN_BAND_II (7)
VCC1 (4)
IN_BAND_V (1)
VCC2 (12)
CPL_OUT (8)
LGE Internal Use Only
MMIC
BIAS and GAIN CONTROL
INPUT
INTER-STAGE
DA
MATCH MATCH
INPUT INTER-STAGE
DA
MATCH
MATCH
Figure 3.2.3.1 SKY77196 Functional Block Diagram
Figure 3.2.3.1 SKY77196 Functional Block Diagram
- 22 -
3. TECHNICAL BRIEF
MODULE
OUTPUT
PA
MATCH
OUTPUT
PA
MATCH
Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LG-C395
LG840G
LG-C395 GU295
(10) OUT_BAND_II
(14) OUT_BAND_V