LG GW520 - Audio

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. BB Circuit Technical brief
GW520 service manual
3.13 Audio
3.13.1 Audio amplifier
GW520 use external audio AMP(MAX9877) for headphone.
The MAX9877 combines a high-efficiency Class D audio power amplifier with a stereo Class AB
capacitorless DirectDrive™ headphone amplifier. Maxim’s 3
rd
generation, filterless Class D amplifier
with active emissions limiting technology provides Class AB performance with Class D efficiency.
The MAX9877 delivers up to 725mW from a 3.7V supply into an 8Ω load with 87% efficiency to
extend battery life.
[Figure 3.13.1-1] Audio CODEC circuit diagram
GW520 service manual
3.13.2 Microphone circuit
MIC300 is used both as a main and as a video .
GW520 service manual
[Figure 3.13.2-1] Microphone circuit diagram
(SUSY0024804)
PRSB6.8CD301
TP303
1uC313
C312 1u
1u
C325
C300
1u
PRSB6.8C
0R307
D300
R303 0
FB300
120
C309
39p
C318
39p
C317
39p
1uC307
VBAT
C323
39p39p
C322
C310
39p
TP302
4.7u
C301
C304 1u
C302
C308
1u
1u
CN300
1
2
OUT+
B5
OUT-
C4
PGND
C5
PVDD
RXIN+
D4
B4
RXIN-
SCL
C3
SDA
B3
B1
VDD
A3
VSS
B2
BIAS
C1N
A4
C1P
A5
D3
GND
HPL
A2
HPR
A1
INA1
D2
INA2
D1
C2
INB1
C1
INB2
D5
EUSY0360201
MAX9877AEWP_TG45
U300
HSO_R
HSO_L
EAR_SPK_N
EAR_SPK_P
RADIO_OUT_L
RADIO_OUT_R
I2C1_SDA
I2C1_SCL
100nHL305
MIC300
G12
3G2
O4
1P
100nHL304 SUMY0010609
SPU0410HR5H-PB
0.1u
C347
C346
0.1u
L303
100nH
C345
DNI
0R320
R321
DNI
ICVS0505500FR
VA30 0
27p
C349
C35127p
C350
100p
C352
10u
MIC_N
MIC_P
VMIC_GND
VMIC_P