HA17384SPS Datasheet, PDF (24/29 Pages) Hitachi Semiconductor – High Speed Current Mode PWM Control IC for Switching Power Supply

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
Application Circuit Example (2)
When the error amplifier is used
Commercial
AC 100V
Line filter
Rectifier bridge diode
−
+
141V
+ _{100µ 220k}
− 200V 1/4W
2SA1029
10k
10k
47k HA17431
V_IN
16.4V
HRP32
P
10µ ⁺ B
50V −
The circuit for
output current limiter _HA17384H,
HA17385H
SBD
HRP24
Transformer specification
example
EI-22 type core
(H7C18 × 06Z)
Gap length
lg = 0.3mm
Transformer coil example
P: 0.5∅80T/570µH
S: 0.5∅16T Bifiler/22µH
B: 0.2∅44T/170µH ₊
S ₊ 1.8k
330
− _1000µ
10V
3.3µ
+
−
3.3k ^DC
5V, 3A
OUTPUT
B
4.7k
HA17431
−
150k
R_T
10k
COMP
100p
FB
CS
0.1µ
Vref
V_IN
OUT
2SK1567
51
Photocoupler
4.7k (for output control)
R_T/C_T
GND
C_T
3300p
1k
1
470p 1k
2W
When the error
amplifier is not used
Vref
COMP
OVP input
Bleeder resistor
(adjuster according
to the rating of the
Photocoupler)
FB 0.8mA V_IN
CS
OUT
R_T/C_T
GND
(Operation Theory)
On the secondary side (S) of the flyback converter,
error amplification is carried out by a shunt
regulator and photocoupler.
The voltage of the backup coil (B) is not monitored,
which differs from the application example (1).
In addition, OVP operates on the secondary side
(S) using a photocoupler.
Refer to the application example (1) for the other
notes.
Figure 13 Secondary Voltage Sensing Flyback Converter
Rev.3.00 Jun 15, 2005 page 24 of 28