This part is a kind of semiconductor called BAT54.

Function of this product has SMALL SIGNAL SCHOTTKY DIODE.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

® BAT54, A, C, S SMALL SIGNAL SCHOTTKY DIODE FEATURES AND BENEFITS A K1 A VERY SMALL CONDUCTION LOSSES NEGLIGIBLE SWITCHING LOSSES LOW FORWARD VOLTAGE DROP SURFACE MOUNT DEVICE K Nc A K1 K2 A K K2 BAT54 DESCRIPTION Schottky barrier diodes encapsulated in a SOT-23 small SMD packages. Double diodes with different pining are available. K A1 A2 A2 A1 A1 K2 BAT54A A2 K K1 A2 A1 K2 K1 BAT54C SOT-23 BAT54S ABSOLUTE RATINGS (limiting values) Symbol VRRM IF IFSM Ptot Tstg Tj TL Parameter Repetitive peak reverse voltage Continuous forward current Surge non repetitive forward current Power dissipation (note 1) Maximum storage temperature range Maximum operating junction temperature * Maximum temperature for soldering during 10s tp=10ms sinusoidal Tamb = 25°C Value 30 0.3 1 250 - 65 [ ... ]

BAT54 PDF Datasheet Download