m51996ap Renesas Electronics Corporation., m51996ap Datasheet - Page 26

• Manufacturer Part Number: m51996ap
• Description: Switching Regulator Control
• Manufacturer: Renesas Electronics Corporation.

M51996AP/AFP
3. OVP setting method using the induced third winding voltage on fly back system
4. Method to control for ON/OFF using the OVP terminal
REJ03D0836-0201 Rev.2.01 Nov 14, 2007
Page 26 of 35
For the over voltage protection (OVP), the induced fly back type third winding voltage can be utilized, as the
induced third winding voltage depends on the output voltage. Figure 21 shows one of the example circuit diagram.
You can reset OVP to lower the OVP terminal voltage lower than V
So you can control for ON/OFF using this nature.
The application is shown in figure 22.
The circuit turns off by SW OFF and turns on by SW ON in this application.
Of course you can make use of the transistor or photo-transistor instead of SW.
Figure 21 OVP Setting Method Using The Induced Third Winding Voltage on Fly Back System
Figure 22 Method to Control for ON/OFF Using The OVP Terminal
M51996A
V
GND
CC
5.1 k
REG
OVP
SW
470 Ω
ON/OFF
M51996A
+
C
VCC
THOVPL
.
Main
transformer
third winding