LG G1610, Service Manual

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3. TECHNICAL BRIEF
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3.2 Power Amplifier Module (RF3133, U400)
The RF3133 is a high-power, high-efficiency power amplifier module with integrated
power control. The device is self-contained with 50ߟ input and output
terminals. The power control function is also incorporated, eliminating the need for
directional couplers, detector diodes, power control ASICs and other power control cir-
cuitry;
this allows the module to be driven directly from the DAC output.
The device is designed for use as the final RF amplifier in GSM 850, E-GSM 900, DCS
and PCS handheld digital cellular equipment and other applications in the
824-849 MHz, 880-915 MHz, 1710-1785 MHz, and 1850-1910 MHz bands.
On-board power control provides over 37 dB of control range with an analog voltage
input (TX_RAMP); and, power down with a logic “low” for standby operation
(TX_ENABLE).
External control (BAND_SELECT) is used to select the GSM or DCS band with a logic
high or low. A logic low enables the GSM band whereas a logic high enables the DCS
band.
Figure 3-5 Functional Block Diagram of RF3133
1 DSC/PCS IN
2
3
4
5
6
7
BAND SELECT
TX ENABLE
VBATT
VREG
VRAMP
GSM IN
DSC/PCS OUT
2
C
C
V
2
C
C
V
VCC OUT
GSM OUT
11
8
12
10
9