Audio - LG GS290 Service Manual

3. TECHNICAL BRIEF

3.11. Audio

GS290 Audio signal flow diagram as following diagram.
Figure 14 Audio signal flow diagram
LGE Internal Use Only - 44 - Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.12.1. Audio amplifier
Audio amplifier sub system IC is an audio power amplifier capable of delivering 1.25W of continuous average
power into a mono 8Ω load, 42mW per channel of continuous average power into stereo 32Ω single-ended (SE)
loads. The LM49151 features 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.
VBAT
C311 C320
VIO_2V62
0.1u 2.2u
C364 220n E1
EAR_P
INM+
C365 220n D1
EAR_N INM-
C347 220n
FM_AUDIO_L
C350 1u
C1
BB_SND_L
INL
C351 1u
BB_SND_R C2
INR LM49151TLX
C321 220n
FM_AUDIO_R
C3
BYPASS
A1
I2CVDD
B2
I2C_SDA SDA
B3
I2C_SCL SCL
C361 C313
0.1u 4.7u
R348
0
EAR_GND
Figure 15 Audio amplifier PMIC
3.12.2. Microphone circuit
MIC
FB305
MAIN_MIC_P
BLM15AG121PN1
FB306
MAIN_MIC_N
BLM15AG121PN1
L303
VMIC_P
100n
C322 C318
C307
47p
27p 27p
VMIC_N
Figure 16 Microphone circuit
Copyright © 2010 LG Electronics. Inc. All right reserved. - 45 -
Only for training and service purposes
3. TECHNICAL BRIEF
A4
LSOUT+ SPK_RCV_P
A3
LSOUT-
SPK_RCV_N
D2
SET
U304
E3
HPL HSO_L
E2
HPR HSO_R
C343 C342
C363
R330
27p 27p
C362
C319 100K
0.1u
2.2u
2.2u
C373 22n
MIC300
1
OUT
C374 22n
2
G1
3
G2
4
G3
5
PWR
6
G4
SPM0410LR5H-QB
C314
VA300 VA302
1u
LGE Internal Use Only