This part is a kind of semiconductor called B2100Q.

Function of this product has SCHOTTKY BARRIER RECTIFIER.

Manufacturers : Diodes

Image and pinout :

Some of the text within the PDF file :

Green B270Q -B2100Q 2.0A HIGH VOLTAGE SCHOTTKY BARRIER RECTIFIER Product Summary (@ +25°C) B270Q VRRM (V) 70 IO (A) 2.0 VF Max (V) 0.79 B280Q VRRM (V) 80 IO (A) 2.0 VF Max (V) 0.79 B290Q VRRM (V) 90 IO (A) 2.0 VF Max (V) 0.79 B2100Q VRRM (V) 100 IO (A) 2.0 VF Max (V) 0.79 IR Max (µA) 7 IR Max (µA) 7 IR Max (µA) 7 IR Max (µA) 7 Description and Applications This Schottky Barrier Rectifier is designed to meet the general requirements of commercial applications. It is ideally suited for use as a:  Polarity Protection Diode  Re-Circulating Diode  Switching Diode Features and Benefits  Schottky Barrier Chip  Guard Ring Die Construction for Transient Protection  Low Power Loss, High Efficiency  Surge Overload Rating to 50A Peak  For Use in Low Voltage, [ ... ]

B2100Q PDF Datasheet Download