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(2) MIDI IC (YMU762, U204)
The phone uses melody IC which makes the robust joyful melody sounds.
6 signals (MIDI_RST, ADD00, RD, MIDI_CS, WR, MIDI_IRQ) from AD6525 are used to control the
melody IC.
Melody data (DATA[8:15]) is transferred to melody IC and played by the dual mode speaker.
External 3.3V LDO (U206) is used for the MIDI chip because the maximum output current of analog
amplifier in melody IC is 300mA.
13MHZ
MIDI_RST
ADD00
MIDI_CS
MIDI_IRQ
DATA08
DATA09
DATA10
DATA11
DATA12
DATA13
DATA14
DATA15
Figure 3-19 Circuit Diagram of MIDI-IC and external LDO.
2V8_VMEM
R208
0
1
R211
0
CLK1
4
_RST
30
A0
31
RD
_RD
29
_CS
5
NC
28
WR
_WR
3
_IRQ
27
D0
26
D1
25
D2
24
D3
23
D4
22
D5
21
D6
20
D7
C220
R228
PLLC
6
3.3K
1000p
VREF
9
C227
0.1u
IOVDD
32
VDD
7
C230
0.1u
VSS
8
3V3_VMIDI
U206
VBAT
1
VOUT
2
VIN
C219
3
2.2u
VOUT_SE
(1608)
C238
10u
11
HPOUT_R
10
C215
HPOUT_L
R212
0.01u
33K
12
EQ1
13
EQ2
R213
82K
14
EQ3
2
LED
19
MTR
U204
YMU762
17
SPOUT1
SPOUT2
18
3V3_VMIDI
SPVDD
15
C229
0.1u
16
SPVSS
LP3981ILD-3.3
6
VEN
MIDI_PWR_EN
5
BYPASS
4
GND1
C221
GND2
0.1u
7
- 35 -
3. TECHNICAL BRIEF
C216
390p
SPK+
SPK-
C222
C223
47p
47p
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