Only For Training And Service Purposes - LG KF700 Service Manual

3.5.9 FM Radio (U103 : SI4702-C19-GM)
The Si4702's patented digital low-IF architecture reduces external components and eliminates the
need for factory adjustments. The receive (RX) section integrates a low noise amplifier (LNA)
supporting the worldwide FM broadcast band (76 to 108 MHz). An automatic gain control (AGC) circuit
controls the gain of the LNA to optimize sensitivity and rejection of strong interferers.
FM_CONTROL
C158 100p
FM_ANT
FM_BUSEN
FM_I2C_SCL
FM_I2C_SDA
SLEEP_CLK
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Only for training and service purposes

21
1
NC1
2
FMIP
3
RFGND
4
GND1
5
_RST
TP100
TP101
TP102
[Fig. 3.9] FM Radio system architecture in the KF700
C156
1u
20 19 18 17 16
15
GND3
14
U103
LOUT
13
ROUT
SI4702-C19-GM
1 2
GND2
11
VD
6 7 8 9 10
C169
0.1u
- 31 -
3. TECHNICAL BRIEF
VREG_MSMP_2.7V
C157
10n
FM_AUDIO_L
FM_AUDIO_R
VREG_MSMP_2.7V
LGE Internal Use Only