Figure 3.2.4.1
FM tuning circuit diagram
C58
472
XT1
32.768KHz
C60
475/X5R
C61
473
L24
601 DCR<350m
C76
104
L18
33nH
2%
D10
BB202
R70
100K
R68
10K
U9
TEA5767HN
N.C
1
N
.C
4
0
CPOP
2
VCOT1
3
VCOT2
4
VCOVCC
5
DGND
6
DVCC
7
DATA
8
CLOCK
9
N.C
10
W
/R
11
B
U
S
M
1
2
B
U
S
E
N
1
3
S
W
P
1
1
4
S
W
P
2
1
5
X
TA
L
1
1
6
X
TA
L
2
1
7
P
D
L
F
1
8
P
H
L
F
1
9
N
.C
2
0
N.C
21
LAVO
22
RAVO
23
TMUTE
24
MPXO
25
VREF
26
TCIFC
27
DIFL1
28
DIFL2
29
N.C
30
N
.C
3
1
IF
G
A
I
3
2
A
G
N
D
3
3
A
V
C
C
3
4
R
F
I1
3
5
R
F
G
N
D
3
6
R
F
I2
3
7
T
C
A
G
C
3
8
L
O
O
P
S
W
3
9
C62
473
R67
18K
C66
103
C56 101
C64
333
R69
22R
L16
120nH
C65
393
C59
47PF
R66
10R
D11
BB202
FDGND
FSGND
FDGND
FSGND
FM_3V3
FDGND
FM_3V3
FM_3V3
FDGND
FSGND
FM_3V3
FDGND
FM_ANT
I2C_SCL
I2C_SDA
C63
473
C73
22PF
L17
33nH
2%
R73
22R
C57 27PF
C67 333
C68
104
L23 601 DCR<350m
C71
102
FM_ANT
L8
601 DCR<350m
L7
601 DCR<350m
N E C T A R - I
C72
223
R72
33K
C75
102
FSGND
FSGND
FSGND
FDGND FDGND
FSGND
FSGND
FDGND
5767R
5767L
C74
223
There is firmware of the player’s working inside Flash and all tasks are completed by CPU to send
out relevant order after the data exchange between CPU and Flash. When the player power on, 3.3V
voltage supplies power for Flash through VCC, /CE inputs 3.3V high level signal and Flash begins to work
effectively. When playing video files, /RE is high level, Flash performs the operation of read out. When
files are written in through USB data line or recording through microphone, /WE is high level and Flash
performs the operation of writing in. The operation of read out and writing in is performed through
I/O1~I/O8 dateladdress lines.
3.2.4 FM tuning circuit
1. FM tuning circuit diagram is shown in the figure 3.2.4.1
2. Working principle: tuning circuit is composed of the micro digital tuning IC TEA5767 of Philips
Company and peripheral circuit. C56, C57, C58, C59, L16 is the antenna input matching circuit of FM
module; variant diode D10, D11 and winding inductor L17, L18 is frequency selection tuning circuit in FM
module. The control of FM adopts IIC bus control means and 9, 10 of TEA5767 are data and control
lines.
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