LG KS360 Service Manual page 47

3. TECHNICAL BRIEF
3.15.1 Audio amplifier
We use MAX9877 Audio AMP, which have speaker & headphone amplifiers. An audio signal path can
be selected by I2C command.
3.15.2 Microphone circuit
LGE Internal Use Only
AUDIO AMP SUB SYSTEM & SIGNAL DISTRIBUTOR
C304 1u
A4
C1N
C305 1u A5
C1P
C308 1u D1
BB_SND_R INA2
C309 1u D2
BB_SND_L INA1
C311 1u C1
FM_SND_R INB2
C312 1u
C2
FM_SND_L INB1
B2
BIAS
B3
i2C_SDA SDA
C3
I2C_SCL SCL
D4
RXIN+
B4
RXIN-
C315
1u
Figure 17. Audio AMP Circuit Diagram
MIC MIC
C321
39p
C320
MIC_N
C319
22n
39p
C318
MIC_P
22n
C317
39p
Figure 18. Microphone Circuit Diagram
VBAT
C301
C302
1u
1u
A1 R313 0
HPR
A2 R314 0
HPL
U303
MAX9877AEWP_TG45
D5
OUT+
B5
OUT-
MICBIAS
MIC300
L304
1
P
2
100nH
G1
3
G2
4
O
L303
SPU0409HE5H-PB
100nH
VA300 C322
10u
Copyright © 2008 LG Electronics. Inc. All right reserved.
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HSO_R
HSO_L
SPK_P
SPK_N
Only for training and service purposes