This part is a kind of semiconductor called 3DD5017.

Function of this product has CASE-RATED BIPOLAR TRANSISTOR.

Manufacturers : JILIN SINO-MICROELECTRONICS

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Some of the text within the PDF file :

R µÍÆ·Å´ó¹Ü¿Ç¶î¨ÄË«¼Ð;§Ìå CASE-RATED BIPOLAR TRANSISTOR FOR TYPE 3DD5017 FOR LOW FREQUENCY 3DD5017 Ö÷Òª²ÎÊý BVCBO IC VCE(sat) tf ÓÃ; z ²ÊÉ«µçÊÓ»ú¿ª¹ØµçÔ´ µç· MAIN CHARACTERISTICS 1200 12 0.5 0.3 ¦Ì V A V(max) s(max) ·â×° Package TO-3P(H)IS APPLICATIONS z Switching power supply for color TV. 1 2 3 ²úÆ·ÌØÐÔ z 3DD5017 ÊÇ ¸ß·´Ñ¹ó¦Âʾ§ÌåÜ¡£ ÔìÖвÉÓõÄÖ÷Òª¹¤ÒÕ¼ ÊõÓУº¸ßѹ̨Ã湤ÒÕ¼ Êõ¡¢ÈýÖØÀ©É¼µ ÓÃËÜÁÏÈ«°ü·â½á¹¡£ £¨ RoHS£Æ·¡£©²ú NPN Ë«¼ÐÍ ÖÆ FEATURES z 3DD5017 is high breakdown voltage of NPN bipolar transistor. The main process of manufacture: high voltage mesa type process, µÈЧç· EQUIVALENT CIRCUIT [ ... ]

3DD5017 PDF Datasheet Download