This part is a kind of semiconductor called 2SD5703.

Function of this product has Power Transistor.

Manufacturers : Inchange Semiconductor

Image and pinout :

Some of the text within the PDF file :

INCHANGE Semiconductor isc Product Specification isc Silicon NPN Power Transistor 2SD5703 DESCRIPTION ·High Breakdown Voltage：VCBO= 1500V (Min) ·High Switching Speed ·Low Saturation Voltage APPLICATIONS ·Designed for color TV horizontal output applications ABSOLUTE MAXIMUM RATINGS(Ta=25℃) SYMBOL PARAMETER VCBO Collector-Base Voltage VCEO Collector-Emitter Voltage VEBO Emitter-Base Voltage w w s c s i . w VALUE UNIT 1500 V 800 V 6 V 10 A 30 A 70 W n c . i m e IC Collector Current- Continuous IC Collector Current- Pulse Collector Power Dissipation @ TC=25℃ PC TJ Junction Temperature 150 ℃ Tstg Storage Temperature Range -55~150 ℃ isc Website：www.iscsemi.cn INCHANGE Semiconductor isc Product Specification [ ... ]

2SD5703 PDF Datasheet Download