Table of Contents
Advertisement
3. TECHNICAL BRIEF
3.10 Microphone
The microphone is placed to the front cover and contacted to main PCB. The audio signal
ispassed to AIN2P and AIN2N pins of AD6535. The voltage supply VMIC is output
fromAD6537B, and is a biased voltage for the AIN2P. The AIN2P andAIN2N signals are then
A/Dconverted by the voicebandADC part of AD6537B.The digitized speech (PCM 8KHz ,16KHz)
isthen
passed to the DSP section of AD6527 for processing (coding, interleaving etc).
M
C I
_
P
M
C I
_
N
3.11 Main Speaker
In the case of B2000, The main speaker is driven directly from AD6537B AOUT1P and
AOUT1N pins and the gain is controlled by the PGA in an AD6537B.
V
B
A
T
C
2
2
0
1
0
u
S
P
K
_
P
S
P
K
_
S
E
L
R
E
C
_
P
2
V
5
_
V
R
2
0
3
2
2 .
K
R
2
0
7
R
2
0
8
1
0
0
0
C
2
1
0
3
9
p
C
2
1
1
R
2
1
0
1
0
0
0
1 .
u
Figure 3-28 Connection between Microphone and AD6537B
U
2
0
2
N
L
A
S
4
6
8
4
M
R
2
1
1
0
V
+
N
O
2
2
9
N
O
1
C
O
M
2
3
8
C
O
M
1
N I
2
4
7
N I
1
N
C
2
5
6
N
C
1
G
N
D
M
C I
R
2
0
0
1
K
C
2
0
1
C
2
0
2
1
0
u
3
9
p
C
2
0
9
3
9
p
C
2
1
3
C
2
1
4
R
2
1
4
3
9
p
3
9
p
2
2 .
K
C
L
O
S
E
T
O
M
C I
C
2
9
9
N
A
C
N
2
0
0
1
S
P
K
_
N
2
C
2
9
8
N
A
R
E
C
_
N
- 42 -
M
C I
2
0
0
1
2
O
B
4
1 -
5
L
4
- 2
C
3
3
L
V
A
2
0
0
V
A
2
0
1
A
V
L
5
M
0
2
2 -
0
0
A
V
L
5
M
0
2
2 -
0
0
R
E
C
E
V I
E
R
S /
P
E
A
K
E
R
S
E
L
E
C
I T
S
P
K
_
S
E
L
O
U
T
L
O
W
R
E
C
E
I H
G
H
S
P
E
A
O
N
P
U
T
V I
E
R
K
E
R
Advertisement
Table of Contents
