This part is a kind of semiconductor called BLD139D.

Function of this product has BLD SERIES TRANSITORS.

Manufacturers : Red Diamond Optoelctronics

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Some of the text within the PDF file :

BLD139D BLD 系列晶体管/BLD SERIES TRANSISTORS ◆应用:节能灯 电子镇流器 电子变压器 开关电源 ◇Applications:Fluorescent Lamp Electronic Ballast Electronic Transformer Switch Mode Power Supply ◆特点:耐压高 开关速度快 安全工作区宽 符合 RoHS 规范 ◇Features:High Voltage Capability High Speed Switching Wide SOA RoHS Compliant ◆最大额定值(Tc=25℃) ◇Absolute Maximum Ratings(Tc=25℃) 参数 Parameter 集电极-基极电压 Collector-Base Voltage 集电极-发射极电压 Collector-Emitter Voltage 发射极-基极电压 Emitter-Base Voltage 集电极电流 Collector Current 集电极耗散功率 Collector Power Dissipation 最高工作温度 Junction Temperature 贮存温度 Storage Temperature 符号 Symbol VCBO VCEO VEBO IC PC Tj Ts [ ... ]

BLD139D PDF Datasheet Download