Only For Training And Service Purposes - LG TU550 Service Manual

3. TECHNICAL BRIEF
3.5.6 GSM/GPRS/EDGE Power amplifier (U102 : AND0041)
This power amplifier module is designed in a low profile (1.3 mm) and supports dual, tri and quad band
applications for GMSK and 8-PSK modulation schemes using a polar architecture. There aretwo
amplifier chains, one to support GSM850/900 bands, the other for DCS/PCS bands.
The module includes an internal reference voltage and integrated power control scheme for use in
both GMSK and 8-PSK operation. This facilitates fast and easy production calibration and reduces the
number of external components required to complete a power control function. The amplifier's power
control range is typically 55 dB, with the output power set by applying an analog voltage to VRAMP.
All of the RF ports for this device are internally matched to 50Ω . Internal DC blocks are provided at
the RF inputs.
LGE Internal Use Only
Figure 3.5.6-1 GSM PA functional block diagram
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Only for training and service purposes