SRP Hitachi Semiconductor, SRP Datasheet - Page 24

• Manufacturer Part Number: SRP
• Description: High Speed Current Mode PWM Control IC for Switching Power Supply
• Manufacturer: Hitachi Semiconductor

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
Application Circuit Example (1)
24
10k
HA17431
Notes:
Snubber circuit
example
10k
47k
FRD
DFG1C8
2SA1029
470p
Commercial
AC 100V
1kV
10k
1.
2. Check the wiring direction of the transformer coil.
3. Insert a snubber circuit if necessary.
4. OVP function is not included in HA17384SPS/SRP.
R
T
Figure 12 Primary Voltage Sensing Flyback Converter
C
3300p
: PRIMARY GND,
51
T
150k
P
Line filter
S
470p
100p
20k
3.6k
(Opetation Theory)
Because this circuit is a flyback type, the voltages in the
primary (P), secondary (s) coils of the transformer and
backup (B) coil are proportional to each other. Using this,
the output voltage of the backup coil (V
at constant 16.4V. (The voltage of the point divided by
resistors of 20k and 3.6k is 2.5V).
COMP
FB
CS
R
1k
T
: SECONDARY GND.
HA17384H,
HA17385H
/C
T
Rectifier bridge diode
+
16.4V
V
IN
+
1k
GND
OUT
Vref
100
200V
V
50V
10
IN
141V
+
51
HRP32
220k
1/4W
0.1
B
P
2SK1567
1
2W
SBD
HRP24
Transformer coil example
P: 0.5¿80T/570 H
S: 0.5¿16T Bifiler/22 H
B: 0.2¿44T/170 H
Transformer specification
example
EI-22 type core
(H7C18
Gap length
lg = 0.3mm
S
IN
of IC) is controlled
+
1000
10V
06Z)
DC 5V, 3A
OUTPUT
+