Drain (D) pin: Drain output of the internal high-voltage power MOSFET.
Control (C) pin: Input pin of the error amplifier and feedback current for duty cycle control.
Line voltage detection (L) Pin overvoltage, undervoltage protection input pins.
This protection is not required, and this pin can be connected to the input power.
External current Limit (X) pin: The external current limit protects the input pin. This protection is not required, and this pin can be connected to the input power.
Multi-function (M) pins: overvoltage, money, overcurrent protection input pins.
This protection is not required, and this pin can be connected to the input power.
Source (S) pin: The source output pin of the internal high-voltage power MOSFET. Generally, this pin is connected to the input power negative.