Only For Training And Service Purposes - LG -S310 Service Manual

3. TECHNICAL BRIEF
3.17.5 FM External LNA
- Features
. Epitaxial Planar NPN Transistor
. Low Noise Figure, High Gain
. NF=1.1dB,
FM LNA Circuit is designed to improve the FM sensitivity in the FM antenna built in phone. It has collector-
feedback bias to minimize the temperature effect. FM_LNA_EN turn on it while FM function is working
without plugging Ear jack.
LGE Internal Use Only
L703
FM_LNA_EN
22n
C701
1u
C725
FM_ANT_1
330p
[Figure 3.17.5] FM LNA Circuit diagram
R700
5.1
R701 R702
24K 270
C702
3
1 Q700
470n
2
C703
DNI
C704
R703
4.7K
470n
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FM_ANT

Only for training and service purposes