This part is a kind of semiconductor called 3DD4202BD.

Function of this product has HIGH VOLTAGE FAST-SWITCHING NPN POWER TRANSISTOR.

Manufacturers : Jilin Sino-microelectronics

Image and pinout :

Some of the text within the PDF file :

R NPN 型高压功率开关晶体管 HIGH VOLTAGE FAST-SWITCHING NPN POWER TRANSISTOR 3DD4202BD 主要参数 IC VCEO PC(TO-92) PC(TO-251) PC(TO-126) MAIN CHARACTERISTICS 1.5A 400V 1W 10W 20W 封装 Package 用途 z z z z z 充电器 电子镇流器 高频开关电源 高频功率变换 一般功率放大电路 APPLICATIONS z Battery changer z Electronic ballasts z High frequency switching power TO-92 TO-251 supply z High frequency power transform z Commonly power amplifier 产品特性 z 高耐压 z 高电流容量 z 高开关速度 z 高可靠性 z 环保（RoHS）产品 FEATURES z High breakdown voltage z High current capability z High switching speed z High reliability z RoHS product TO-126 订货信息 ORDER MESSAGE 订 货 型 号 Order codes 3DD4202BD-O-T-B-A 3DD4202BD-O [ ... ]

3DD4202BD PDF Datasheet Download