Microphone; Main Speaker - LG KG290 Service Manual

3.10 Microphone

The microphone is placed to the Rear cover and contacted to main PCB. The audio signal is passed to
VINNORP and VINNORN pins of AD6721. The voltage supply VMIC is output from AD6721, and is a
biased voltage for the VINNORP. The VINNORP and VINNORN signals are then A/D converted by the
voiceband ADC part of AD6721.The digitized speech (PCM 8KHz ,16KHz) is then passed to the DSP
section of AD6721 for processing (coding, interleaving etc).
MIC
MIC_PATH_SEL
L AD6721
H AIT813G
MIC_P
C222
MIC_N
Figure 3-12. Connection between Microphone and AD6721

3.11 Main Speaker

Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2V5_VMIC
R221
1K
R227
2.2K
R231 100ohm
39p
C228 0.1u
R232 100ohm
R234
2.2K
ACCDETECT
U16 R190 4.7
JACKSENSE
M15
AIN3L
N14
AIN3R
C152 0.1u
M16
AIN3COMMON
N17
AOUT1P
N16
AOUT1N
T14
AOUT2P1
U14 R122
AOUT2P2
T15 R123
AOUT2N1
U15
AOUT2N2
M17 R124 4.7
AOUT3L
R125 4.7
N15
AOUT3R
C158
39p
2V8_VMEM
U204
NLAS5223BMNR2G
1
VCC
2
MULTI_MIC_P NO1
3
MIC_P COM1
4
MIC_PATH_SEL IN1
5
VINNORP NC1
C216
C219 C215 1u
10u
39p
C223
39p
JACK_DETECT
FM_AUDIO_L
R120 4.7
FM_AUDIO_R
C153
NA
R121 4.7
4.7
ABB_P C154
4.7
39p
ABB_N
AUXOP_L C156 C157
AUXOP_R 39p 39p
C159
39p
- 33 -
3. TECHNICAL BRIEF
10
NO2 MULTI_MIC_N
9
COM2 MIC_N
8
IN2 MIC_PATH_SEL
7
NC2 VINNORN
6
GND
C217
100K
OB4-15L42-C33L
2
1
MIC200
REC_P
REC_N
C155
39p
LGE Internal Use Only