This part is a kind of semiconductor called B0540W.

Function of this product has Surface Mount Schottky Barrier Rectifiers.

Manufacturers : LGE

Image and pinout :

Some of the text within the PDF file :

B0520LW,B0530W,B0540W 0.5AMP. Surface Mount Schottky Barrier Rectifiers SOD-123 0.053(1.35) Max. 0.022(0.55) Typ. Min. Features Low power loss, high efficiency. Guard ring construction for transient protection High conductance Mechanical Data 0.152(3.85) 0.140(3.55) 0.010(0.25) Min. 0.112(2.85) 0.100(2.55) Case: SOD-123, plastic Marking: Date Code and Type Code 0.006(0.15) Typ. Min. 0.067(1.70) 0.055(1.40) Type Code: B0520LW Marking: SD B0530W Marking: SE B0540W Marking: SF Weight: 0.01 grams (approx.) 0.004(0.10) Max. Dimensions in inches and (millimeters) Maximum Ratings and Electrical Characteristics Rating at 25 oC ambient temperature unless otherwise specified. Maximum Ratings Type Number Dimensions in inches and (millimeters) Symbol B0520LW B0530W B0540W Units Peak Re [ ... ]

B0540W PDF Datasheet Download