Front End Module Control; Power Amplifier Module - LG KE600 - Cell Phone Service Manual

3.24. Front End Module control

Implemented in the S-Gold2 (U101) are three outputs which are ANT_SW1, ANT_SW2 and ANT_SW3
for direct control of front end modules with three logic input pins to select RX and TX mode as well as
low and high band operation.
MODE
VDD
VCTRL1
VCTRL2
VCTRL3
2V85_RF
C605 C606
56p 0.1u
GND11
GND10
ANT GND9
1
GND8
GND7

3.25. Power Amplifier Module

The RF3158 (U601) is a high-power, dual-mode amplifier (PA) with integrated power control. This PA
is designed to operate both in a saturated mode for GMSK signaling and in a linear mode for 8PSK
modulation. Featuring input and output terminals that are internally matched to 50 ohms, the PAM is
designed to be the final amplification stage in a dual-mode GSM/EDGE mobile transmit lineup
operating in the 824 MHz to 915 MHz (low) and 1710 MHz to 1910 MHz (high) bands.
Tx 1GHz Tx 2GHz
ON ON
ON ON
OFF ON
OFF OFF
FL601
YGHF-S006T
26
25
24
23
11
Figure 40 FEM schematic
3. TECHNICAL BRIEF
Rx EGSM Rx DCS
ON
OFF
ON
OFF
- 67 -
TX PCS
ON ON
OFF OFF
OFF OFF
ON OFF
R601 100ohm
R602 100ohm
R603 100ohm
C601 C602 C603
39p 39p 39p
ANT_SW1
ANT_SW2
ANT_SW3