SCY99194 Datasheet, PDF (2/40 Pages) ON Semiconductor – Fixed Frequency Current Mode Controller

SCY99194
TYPICAL APPLICATION EXAMPLE
SCY99194
Figure 1. Flyback Converter Application Using the SCY99194
PIN FUNCTION DESCRIPTION
Pin No Pin Name
Function
1
LATCH
Latch−Off Input
2
FB
Feedback + Shutdown pin
3
CS
Current Sense
4
GND
5
DRV
6
VCC
−
Drive output
VCC input
8
HV
High−voltage pin
Pin Description
Pull the pin up or down to latch−off 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 current−mode 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 Start−up
Current Source, Self−Supply 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.
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