Azur 752BD
Service Manual
33
DAC ANALOG POWER SUPPLY
from power board
1.2V DSP PSU for 751BD only used
NO FIT
0.765V
0.765V
NO FIT
NO FIT
NO FIT
NO FIT
380mA
DAC DIGITAL POWER SUPPLY
U1 note:
if the out voltage greater than 6 volt need an diode D1 to protect the decice against input short circuit
because in this case, input voltage falls rapidly while output voltage decrease slowly, some transistor b-e junction of regula
tor
maybe distroyed be capcitance discharge
U2 note:
add diode D8 ,in order to protect input voltage short
because in this case, input voltage falls rapidly while output voltage decrease slowly, some transistor b-e junction of regula
tor
maybe distroyed be capcitance discharge
VIN
GND
VOUT
U1 L7805CV
CE9
1000UF/25V
D1
SID(NC)
+
CE101 1000UF 25V
C19
105
+
CE117
1000UF
25V
C21
105
OUT ADJ
IN
U2
LM317
R1 1K
R2
8.2K
Q21 BC846
R11
100K
R12
2K
R13
47K
D8
RB160M
C22
104
1
3
2
V1
AO4185
3
OUT
1
ADJ
2
IN
U5
LM337
+
CE120
1000UF 25V
C138
105
C148
105
+
CE127
1000UF 25V
R14
8.2K
R142 1K
R178
100K
2
3
1
Q22
BC807
ZD1
16V/0.5W
R205 47K
Q23 BC846
R235
2K
D19
RB160M(NC)
R274
10K
R275
10K
C149
104
1
23
V2
AO4184
L1
10R/100M/2A
L2
10R/100M/2A
FB2
121/0603 2A
FB1
121/0603 2A
CE44
220uF
C316 104
C18
104
2
VFB
3
VREG5
4
SS
5
GND
6
PG
7
EN
8
PGND1
9
PGND2
1
VO
14
VCC
13
VIN
12
VBST
11
SW2
10
SW1
15E-PAD
U13
TPS54325PWPR
L14
1.5uH/1.5A
C20 22μF
C23
222
C8 102
R81
330R/1%
R86
1.1K/1%
R394
10K
C117
105
C118
22μF
C9 104
C134
104
CE45
220uF
2
VFB
3
VREG5
4
SS
5
GND
6
PG
7
EN
8
PGND1
9
PGND2
1
VO
14
VCC
13
VIN
12
VBST
11
SW2
10
SW1
15E-PAD
U15
TPS54325PWPR
L15 1.5uH
C139
22μF
C141
222
C556
102
R82
2.49K/1%
1
2
R115
1.5K/1%
R398
4.7K
C169
105
C170
22μF
FB7
220Z 1206 2A
C10
104
C11
22μF
C607
22μF
C12
22μF
C13
22μF
FB3
121/0603 2A
R83
510R
R89
510R
C14
105
+
CE2 220UF 16V
C165 104
FB9
10R/100M/2A
1
2
3
4
5
6
7
8
9
CN1
CN9P2.5
R325
510R
L6
0R/1206
FB8
0R/1206
C280
103
R56
150K
C279
103
C179
22μF
C172
22μF
D30
RB160M
C281
106
D31
RB160M
C282
475
5V
+12V
MCU_STBY
AGND
+15V
15V
AGND
MCU_STBY
AGND
INPUT_-15V
AGND
AGND
-12V
15V
INPUT_-15V
15V
-15V
DSP3.3V
+5V
+5V
+5V
DSP1.2V
3.3V
DAC_VD_5V#
MCU_STBY
MCU_STBY
+5V
DAC_VD_5V#
AUDIO BOARD
circuit diagram
-31-