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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. 9 Microphone
The microphone is placed to the Front cover and contacted to main PCB. The audio signal is passed
to VINNORP and VINNORN pins of AD6726. The voltage supply VMIC is output from AD6726, and is
a biased voltage for the VINNORP. The VINNORP and VINNORN signals are then A/D converted by
the voice band ADC part of AD6726.The digitized speech (PCM 8KHz ,16KHz) is then passed to the
DSP section of AD6726 for processing (coding, interleaving etc).
CLOSE TO ABB
MIC
39p
C221
C223
0.1u
R221 100ohm
1K
R212
VA205
ICVN0505X150FR
2.2u
C217
39p
C219
2V5_VMIC
ICVN0505X150FR
VA206
SPOB-413S44-RC10BC
MIC201
1
2
C228
39p
100ohm
R219
C227
39p
2.2K
R223
R216
39p
2.2K
C222
VINNORP
VINNORN
Figure 3.9 Connection between Microphone and AD6726
Summary of Contents for KP175
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