Yamaha YMC-700 Service Manual page 84

A B C
YMC-700/YMC-500
MAIN 1/5
1
Q Q
3
CB1 CB2
AC IN
2
3
4
5
T E
L 1 3
6
7
8
IC4, 10, 11: TPS54331
IC2: FA5511N-D1-TE1
CMOS IC for switching power supply control 3A, 28V input, STEP DPWN SWIFT
with ECO-MODE
VCC(6)
CS(8)
REF
9
0.8V/0.68V 5.2 A 15.5V
(7)
5V VCC
0.95mA
UVLO
ENB 15.5V
5V REF
8.5V/7.9V 16.5V/9V
0.8V
OUT
3.5V
ENB (5)
FB
4V
(2)
OUT
PUT
PWM
Dmax
GND
FA5510: 46% w w w
OSC
FA5511: 70% (4)
R
RT CT QB
+0.24V VSENSE 5
Q
S
FF
2 μA
5V Controlled block
RT(1) IS+(3)
SS 4
2 k-ohms
10
★ All voltages are measured with a 10MΩ/V DC electronic voltmeter.
★ Components having special characteristics are marked
and must be replaced
COMP 6
with parts having specifications equal to those originally installed.
★ Schematic diagram is subject to change without notice.
84
D E F
7 1 5
6 3
(59.5)
(163.7)
(0)
(59.8)
IC3
18.0
(15.4)
(4.0)
(4.0)
(2.6)
(1.3) (0)
(0)
(1.3) (15.4)
IC1
19.1
(0)
(2.2)
(0)
18.1
Primary side ground
8.1
4.0
8.1
11.7
11.7
4.0
4.0 4.0 2.5
9 4 2 2 9 6 5 1 3
0 2.5
1.7
0
0
8.1
AC10.2
0
11.7 11.5
to MAIN 2/5
IC5: BA00JC5WT-V5
Voltage regulator
TM
DC/DC converter
TM
1
CTL
EN VIN
3 2
165C
Thermal
Shutdown
1 μA 2 μA
IC6: BD9781HFP-TR
Shutdown
Shutdown Flexible step-down switching regulator
Logic
1.25V
Enable
Enable
Comparator
Threshold Boot
Charge
VIN 1
ECO-MODE ™ Boot
1 BOOT
Minimum Clamp UVLO
2.1V
Error
PWM 12A/V
– PWM
Amplifier Current SOFT
Comparator Latch
x a Sense o START
+
R Q 80m-ohms
+ gm = 92μA/V Gate
DC gain = 800 V/V Logic
ERROR AMP
BW = 2.7MHz Drive S
. i 6
INV
Voltage
Reference
∑ Slope
0.8V Compensation
Shutdown
8 PH Vref
Discharge
Logic
VSENSE
Frequency
Oscillator
Shift
7 GND
Maximum
FB 5
Clamp
G http://www.xiaoyu163.com H
YMC-700 YMC-500
1 5
0
POWER TRANSFORMER
(163.4)
(163.4)
(233.2)
(233.2)
(163.3)
(1.6)
(0)
(1.7)
(2.2)
18.0
(0)
(15.4)
(0)
to MAIN 2/5
to MAIN 2/5
Q Q
3
3.3
0
0
3.3
3.3
0
0
0
0
0
0
13.2
12.9
12.9
Vref -
Driver
+
-0.2
TSD OCP
2 3 4 5
Vcc GND VOUT C
IC7: NJM431U
Adjustable precision shunt regulator
7 1 2 3
ON/OFF EN/SYNC
L:OFF
H:ON REFERENCE ANODE CATHODE
Vref SYNC
u 1 6 3
y
IC8: NJM78M12FA
PWM Voltage regulator
COMPARATOR
LATCH DRIVER IC13: LMV431AIMF
2 SW
RESET Low voltage adjustable precision shunt regulator
OSC TSD
ANODE
V IN
CURENT LIMIT 4 GND
REF CATHODE
3
RT
I J K
2 4
8 9
0
28.0
0
18.1
18.1
0
2.5
0
0 18.0
18.0 12.0
12.0
18.0
18.0
IC8
0 0
0 -18.3
IC6
13.2
0
7 6 3 1 5 1 5 0 8
3.3
9.5 12.4
12.9 0 13.2
2.9
0.8 1.9
1.8 0.9 1.8
3.3
0
8.7
13.2
1.9
IC5
1.8
8.7
4.8
3.3
4.2
2.0
4.2 0
0
0
m
c o IC14: NJM78M05FA
3-terminal positive voltage regulator
IC12: NJM7805FA
. 3-terminal positive voltage regulator
INPUT
INPUT
OUTPUT
OUTPUT
COMMON GND
L M N
2
9 8 9 9
0.7
to MAIN 3/5
18.0 5.1
IC14
18.0 5.1
0
0
IC15
-18.3
-5.0
-18.3 -5.0
to MAIN 2/5
13.2
5.1
IC12
13.2 5.1
0
9 2 4 9 8 2 9 9
W1
6.2
5.1
3.3
3.3
2.6
Page 82 K9
2.6
to DIGITAL_CB381
3.3
0
6.2
0
0
0
0.8
0.9
6.2
0
2.6
0
0.7
0.9
2.6
0
IC15: NJM79M05FA
IN Voltage regulator
COMMON
OUT
OUTPUT
INPUT
GND