HA17384SPS Datasheet, PDF (12/29 Pages) Hitachi Semiconductor – High Speed Current Mode PWM Control IC for Switching Power Supply

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
Power OFF
At power OFF, the input voltage of the transformer gradually decreases and then V_IN of IC also decreases according to
the input voltage. When V_IN becomes lower than 10 V*² or Vref becomes lower than 4.7 V, UVL1 (UVL2) operates
again and the PWM pulse stops.
Note: 2. The value is for the HA17384S/H.
The value is 7.6 V for the HA17385H.
Commercial AC voltage
−
Power switch Line filter
20k
OVP input
3.6k
(Ex: from photocoupler)
+
−
+
100µ
200V
Rectifier
R_B
220k
1/4W
bridge diode HRP32
P
V_IN
C_B
10µ
50V
+
−
B
SBD
ex. HRP24
+
S+
−
DC
output
1000µ ^−
10V
R_T
10k
C_T
3300p
150k
COMP
Vref
100p
FB
V_IN
CS
OUT
V_CS
330p
R_T/C_T
GND
HA17384H,
HA17385H
1k
0.1µ
51
Floating
ground
Power MOSFET
ex. 2SK1567
R_CS
1
2W
Figure 2 Mounting Circut Diagram for Operation Expression
Rev.3.00 Jun 15, 2005 page 12 of 28