LG KF700Q Service Manual page 32

3.5.9 FM Radio (U404 : 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
C455
FM_ANT
FM_BUSEN
FM_I2C_SCL
FM_I2C_SDA
SLEEP_CLK
[Fig. 3.9] FM Radio system architecture in the KF700Q
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
21 20 19 18 17
1
NC1
100p
2
FMIP
3
RFGND
4
GND1
5
_RST
6 7 8 9
- 33 -
3. TECHNICAL BRIEF
C451
C452
1u
0.01u
16
15
GND3
14
LOUT
13
ROUT
12
GND2
11
VD
U404
10
SI4702-C19-GM
C461
0.1u
VREG_MSMP_2.7V
FM_AUDIO_L
FM_AUDIO_R
VREG_MSMP_2.7V
LGE Internal Use Only