HA16120FP HITACHI [Hitachi Semiconductor], HA16120FP Datasheet - Page 33

• Manufacturer Part Number: HA16120FP
• Description: Switching Regulator for Chopper Type DC/DC Converter
• Manufacturer: HITACHI [Hitachi Semiconductor]

Application Examples (2)
This is one example of a circuit that uses the features of the HA16114/120 by operating in
synchronization with a flyback AC/DC converter. Note the following design points concerning the
circuit from the secondary side of the transformer to the SYNC pin of the HA16114/120.
(1) Combination with a flyback AC/DC converter (simplified schematic)
External Synchronization with Primary-Control AC/DC Converter
Diode D prevents reverse current. Always insert a diode here. Use a general-purpose switching
Resistors R
diode.
does not exceed Vref (2.5 V). To maintain operating speed, R
Commer-
cial AC
HRA83
Primary AC/DC converter IC
(HA16107, HA17384, etc.)
+
Error amp.
1
and R
2
form a voltage divider to ensure that the input voltage swing at the SYNC pin
+
CL(CS)
OUT
V
IN
1S2076A
+
Transformer
HA16114P/PJ/FP/FPJ, HA16120FP/FPJ
1S2076A
Step-down
output
(HA16114)
GND
1
SYNC
D
R
R
1
2
2
HA16114,
HA16120
1
OUT
HRP24
+ R
SBD
9
To A of SBD
2
P.GND
should not exceed 10 k .
8
K
A
HRP24
+
V
CL
IN
2SJ296
SBD
10
11
Main DC
output
+
+
Sub DC
output
+
33