This part is a kind of semiconductor called C3457.

Function of this product has 2SC3457.

Manufacturers : Sanyo

Image and pinout :

Some of the text within the PDF file :

Ordering number:EN1580C NPN Triple Diffused Planar Type Silicon Transistor 2SC3457 800V/3A Switching Regulator Applications Features · High breakdown voltage and high reliability. · Fast switching speed (tf : 0.1µs typ). · Wide ASO. · Adoption of MBIT process. Package Dimensions unit:mm 2010C [2SC3457] Specifications JEDEC : TO-220AB EIAJ : SC-46 1 : Base 2 : Collector 3 : Emitter Absolute Maximum Ratings at Ta = 25˚C Parameter Collector-to-Base Voltage Collector-to-Emitter Voltage Emitter-to-Base Voltage Collector Current Collector Current (Pulse) Base Current Collector Dissipation Junction Temperature Storage Temperature Symbol VCBO VCEO VEBO IC ICP IB PC Tj Tstg Conditions PW≤300µs, Duty Cycle≤10% Tc=25˚C Ratings 1100 800 7 3 10 1.5 50 150 –55 to +150 Unit V V [ ... ]

C3457 PDF Datasheet Download