NCP1246 ONSEMI [ON Semiconductor], NCP1246 Datasheet - Page 2

• Manufacturer Part Number: NCP1246
• Description: Fixed Frequency Current Mode Controller for Flyback Converters
• Manufacturer: ONSEMI [ON Semiconductor]

PIN FUNCTION DESCRIPTION
Pin No
1
2
3
4
5
6
8
Pin Name
LATCH
GND
DRV
VCC
FB
CS
HV
Feedback + Shutdown pin
Figure 1. Flyback Converter Application Using the NCP1246
Highïvoltage pin
LatchïOff Input
Current Sense
Drive output
VCC input
Function
ï
TYPICAL APPLICATION EXAMPLE
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Pull the pin up or down to latchïoff the controller. An internal current source
allows the direct connection of an NTC for over temperature detection.
An optocoupler collector to ground controls the output regulation. The part
goes to the low consumption Off mode if the FB input pin is pulled to GND.
This Input senses the Primary Current for currentïmode operation, and
offers an overpower compensation adjustment.
The controller ground
Drives external MOSFET
This supply pin accepts up to 28 Vdc, with overvoltage detection. The pin is
connected to an external auxiliary voltage. It is not allowed to connect
another circuit to this pin to keep low input power consumption.
Connects to the rectified AC line to perform the functions of Startïup
Current Source, SelfïSupply, brownïout detection and X2 capacitor
discharge function and the HV sensing for the overpower protection
purposes. It is not allowed to connect this pin to DC voltage.
NCP1246
2
Pin Description