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3. TECHNICAL BRIEF
LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.12 Audio
KF350 Audio signal flow diagram as following diagram.
3.12.1 Audio amplifier
Audio amplifier sub system IC is an audio power amplifier capable of delivering 1.2 W of continuous
average power into a mono 8ߟ load, 50mW per channel of continuous average power into stereo
32Ω ßŸ single-ended (SE) loads. The MAX9877 features a 32-step digital volume control and ten
distinct output modes. The digital volume control, output modes (mono/SE/OCL) are programmed
through a two-wire I2C interface that allows flexibility in routing and mixing audio channels.
Figure 16 Audio signal flow diagram
Figure 17 Audio amplifier PMIC
BT+
FM
MAX
9877
MIC
BBP
PMB8877
SPK
RCV
FM
Ear M IC
18p
in
/ I
O
R210
20K
C219
1u
C215 1u
27p
C226
2.2u
C212
C222
1u
2.2u
C214
C217
1u
C221 1u
27p
C227
C220
1u
VBAT
VBAT
C213 1u
1000p
C216
1K
R209
8.2
R212
RXIN-
B4
C3
SCL
B3
SDA
VDD
B1
VSS
A3
BIAS
B2
A4
C1N
A5
C1P
GND
D3
A2
HPL
A1
HPR
D2
INA1
D1
INA2
INB1
C2
INB2
C1
D5
OUT+
OUT-
B5
PGND
C4
PVDD
C5
D4
RXIN+
U201
MAX9877AEWP_TG45
1u
C218
R211
8.2
BB_SND_R
AUDIO_IN
SPK_RCV_P
SPK_RCV_N
SDA
SCL
EAR_P
EAR_N
HSO_L
HSO_R
BB_SND_L
FM_SND_R
FM_SND_L