Pin function detail
Drain pin
Drain connection of the output MOSFET. Internal bias is provided for the current source by internal switching of high voltage current during start-up operation. Internal current detection point.
Control pin
Duty cycle error amplifier and feedback current input pin control. The internal shunt regulator is connected to provide bias current during normal internal operation. It is also used as a power bypass and automatic restart\/connection point compensation capacitor.
Source pin
Y Package - The output MOSFET's source is connected to the return of a high voltage power supply. Primary side circuit common and reference points