This part is a kind of semiconductor called C5548A.
Function of this product has 2SC5548A.
Manufacturers : Toshiba
Image and pinout :
Some of the text within the PDF file :
TOSHIBA Transistor Silicon NPN Triple Diffused Type 2SC5548A High Voltage Switching Applications Switching Regulator Applications DC-DC Converter Applications 2SC5548A Unit: mm • High speed switching: tr = 0.5 μs (max), tf = 0.3 μs (max) (IC = 0.8 A) • High collector breakdown voltage: VCEO = 400 V • High DC current gain: hFE = 40 (min) (IC = 0.2 A) Absolute Maximum Ratings (Ta = 25°C) Characteristics Symbol Rating Unit Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current DC Pulse Base current Collector power dissipation Ta = 25°C Tc = 25°C Junction temperature Storage temperature range VCBO VCEO VEBO IC ICP IB PC Tj Tstg 600 400 7 2 4 0.5 1.0 15 150 −55 to 150 V V V A A W °C °C JEDEC ― JEITA ― TOSHIBA 2-7J1A [ ... ]