HA17384SPS Datasheet, PDF (23/29 Pages) Hitachi Semiconductor – High Speed Current Mode PWM Control IC for Switching Power Supply

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
Application Circuit Example (1)
Commercial
AC 100V
−
Line filter
20k
3.6k
Rectifier bridge diode
+
141V
+ _{100µ 220k}
− 200V 1/4W
16.4V
V_IN
10µ
50V
HRP32
P
+B
−
SBD
HRP24
1000µ
10V
+
S ⁺ _{DC 5V, 3A}
− _OUTPUT
−
10k
2SA1029
10k
150k
47k
R_T
10k
HA17431
The circuit for
output current limiter
C_T
3300p
HA17384H,
HA17385H
COMP
100p
FB
CS
R_T/C_T
Vref
V_IN
OUT
GND
0.1µ
51
1k
470p 1k
Transformer specification
example
EI-22 type core
(H7C18 × 06Z)
Gap length
lg = 0.3mm
2SK1567
Transformer coil example
P: 0.5∅80T/570µH
S: 0.5∅16T Bifiler/22µH
B: 0.2∅44T/170µH
1
2W
Notes: 1. : PRIMARY GND, : SECONDARY GND.
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.
Snubber circuit
example
470p
1kV
51
FRD
P
DFG1C8
(Opetation Theory)
Because this circuit is a flyback type, the voltages in the
primary (P), secondary (s) coils of the transformer and
S ^{backup (B) coil are proportional to each other. Using this,}
the output voltage of the backup coil (V_IN of IC) is controlled
at constant 16.4V. (The voltage of the point divided by
resistors of 20kΩ and 3.6kΩ is 2.5V).
Figure 12 Primary Voltage Sensing Flyback Converter
Rev.3.00 Jun 15, 2005 page 23 of 28