Only For Training And Service Purposes - LG GM200 Service Manual

We use MEMS MIC especially effective against RF
Audio ADC and PGA
The Audio ADC is a high-order single-bit sigma-delta ADC that includes a switched-capacitor PGA at the
input.
Digital Filters
The AD6725-ATLAS3H LITE Audio Section provides two digital filters. The voiceband filter is used for
applications with a 8 kHz digital sample rate. The high-quality audio filter is used for applications with
higher digital sample rates.
LGE Internal Use Only
Copyright © 2009 LG Electronics. Inc. All right reserved.

Only for training and service purposes

noise.
L 2 0 7 1 0
M C I _ P
L 2 0 8 1 0 0
M C I _ N
E L C H 0 0 0 5 0
H K 1 0 0 5 R 1
C 2 4 9
C 2 5 5
2 7 p
2 7 p
Figure 3-2-5 GM200 input circuit diagram
2 V 5 _ V M C I
M C I
R 2 2 2
1 K
R 2 2 5
C 2 4 6 C 2 4 5
1 0 0 p 1 0 u
2 2 0 0
L 2 0 6
1 0 0 n H
M C I
0 n H
1
O U T
2
n H G 1
3
G 2
4
0 9
G 3
0 J 5
P W
6
V A 2 0 9 V A 2 1 0
G 4
C 2 5 6
S P M
3 9 p
S U
S E V Y 0 0 0 5 4 0 2
C h a n g e d o t N e w
C I V S 0 5 0 5 5 0 0 F R
- 37 -
3. TECHNICAL BRIEF
2 0 1
R
0 4 1 0 L R 5 H - Q B
M Y 0 0 1 0 6 1 0
M C I 0 ( 8 0 8 1 8 J e n ) o
LGE Internal Use Only