This part is a kind of semiconductor called 2SD400.

Function of this product has PNP / NPN Epitaxial Planar Silicon Transistors.

Manufacturers : Sanyo Semicon Device

Image and pinout :

Some of the text within the PDF file :

Ordering number : EN0199 2SB544 / 2SD400 Preliminary SANYO Semiconductors DATA SHEET 2SB544 / 2SD400 PNP / NPN Epitaxial Planar Silicon Transistors Low-Frequency Power Amplifier Electronic Governor Applications Specifications ( ) : 2SB544 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) Collector Dissipation Junction Temperature Storage Temperature Symbol VCBO VCEO VEBO IC ICP PC Tj Tstg Electrical Characteristics at Ta=25°C Conditions Parameter Collector Cutoff Current Emitter Cutoff Current DC Current Gain Gain-Bandwidth Product Output Capacitance Collector-to-Emitter Saturation Voltage Base-to-Emitter Saturation Voltage Collector-to-Base Breakdown Voltage [ ... ]

2SD400 PDF Datasheet Download