This part is a kind of semiconductor called STR-W6253D.

Function of this product has PWM Off-Line Switching Regulator ICs.

Manufacturers : Sanken

Image and pinout :

Some of the text within the PDF file :

STR-W6251D, STR-W6252D, and STR-W6253D PWM Off-Line Switching Regulator ICs Features and Benefits ▪ TO-220 fully-molded package with 6 pins ▪ Current mode PWM control ▪ PWM and frequency modulation functions: reduces EMI noise, simplifies EMI filters, and cuts cost by external part reduction ▪ Built-in Slope Compensation circuit: avoids subharmonic oscillation ▪ Automatic Standby Mode function (Input Power < 40 mW at no load) ▫ Normal operation: PWM mode ▫ Light load operation: Standby mode (burst oscillation) ▪ Built-in Audible Noise Suppression function during Standby mode Continued on the next page… Package: TO-220F-6L Not to scale Description STR-W6200D series are power ICs for switching power supplies, incorporating a power MOSFET and a current mode PWM controller [ ... ]

STR-W6253D PDF Datasheet Download