LG GX500 Service Manual page 57

3. TECHNICAL BRIEF
GX500 Operational Description
3.11.1 Audio amplifier
The LM49151 is a fully integrated audio subsystem designed for portable handheld applications such as
cellular phones.
The LM49151 combines a 1.25W mono E2S class D amplifier, 125mW Class AB earpiece driver, 42mW/channel
stereo ground referenced headphone drivers, volume control, input mixer/multiplexer, and speaker
protection into a single device..
Figure 3-21 Audio amplifier
3.11.2. Microphone circuit
MAIN_MIC_N
MAIN_MIC_P
Figure 3-22 Microphone circuit
LGE Internal Use Only
LG Electronics
AUDIO AMP SUB SYSTEM
2V62_VIO
C705 1u
RCV_P
C706 1u
RCV_N
E1
D1
C703 220n
C1
AMP_IN_L
C707 220n
C2
AMP_IN_R
C3
A1
B2
I2C1_SDA
B3
I2C1_SCL
C708
0.1uF
C713
2.2u
MAIN MIC
1V8_MIC_BIAS
C311
47P
C316 C307
47p 47p
58/143
VBAT
FB701
C701
C712
10u
0.1u
A4
INM+ LSOUT+
A3
INM- LSOUT-
D2
INL SET
U701
LM49151TL
INR
E3
HPL
BYPASS
I2CVDD
SDA
E2
SCL HPR
C711 C710
0.1uF 27pF 27pF
C702
C704 C709
2.2uF 2.2uF
L303
100NH
C318
2.2u
VA302
VA301
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Copyright © 2010 LG Electronics. Inc. All right reserved.
Revision A
SPK_P
SPK_N
HSO_L
HSO_R
MIC301
1
P
2
G1
3
G2
4
O
SPU0410HR5H-PB
Only for training and service purposes
LGE Property