LG L602i Service Manual page 28

3. TECHNICAL BRIEF
3.5.3 UMTS Power Amplifier (U1005, U1007)
The AWT6277 (AWT6307) meets the increasing demands for higher output power in UMTS handsets.
The PA module is optimized for VREF = +2.85 V, a requirement for compatibility with the Qualcomm®
6250 chipset. The device is manufactured on an advanced InGaP HBT MMIC technology offering
state-of-the-art reliability, temperature stability, and ruggedness. Selectable bias modes that optimize
efficiency for different output power levels, and a shutdown mode with low leakage current, increase
handset talk and standby time.
The self-contained 4 mm x 4 mm x 1.1 mm surface mount package incorporates matching networks
optimized for output power, efficiency, and linearity in a 50 Ω system.
Figure1.5.3-1 UMTS PA functional block diagram
3.5.4 Thermistor (R1029)
This thermistor senses temperature variations around UMTS PA to adjust PA gain deviation for assure
compliance with the applicable transmit power control standards. Negative temperature compensation
thermistor is used in the L602i.
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