This part is a kind of semiconductor called SD6863.

Function of this product has CURRENT MODE PWM+PFM CONTROLLER.

Manufacturers : SILAN MICROELECTRONICS

Image and pinout :

Some of the text within the PDF file :

SD686X CURRENT MODE PWM+PFM CONTROLLER WITH BUILT-IN HIGH VOLTAGE MOSFET DESCRIPTION SD686X is current mode PWM+PFM controller with built-in highvoltage MOSFET used for SWPS, with low standby power and low start current for power switch. In standby mode, the circuit enters burst mode to reduce the standby power dissipation. The switch frequency is 25~67KHz with jitter frequency for low EMI. Built-in peak current compensation circuit makes the limit output power stable even with different input AC voltage. Limit output power can be adjusted through the resistor. Maximum peak current compensation during power-on reduces pressure on transformer to avoid saturation, the peak current compensation will decrease for balance after power-on. It integrates various protections such as undervoltage lo [ ... ]

SD6863 PDF Datasheet Download