This part is a kind of semiconductor called STPS20L15D.

Function of this product has LOW DROP OR-ing POWER SCHOTTKY DIODE.

Manufacturers : ST Microelectronics

Image and pinout :

Some of the text within the PDF file :

® STPS20L15D/G LOW DROP OR-ing POWER SCHOTTKY DIODE MAIN PRODUCT CHARACTERISTICS IF(AV) VRRM Tj (max) VF (max) FEATURES AND BENEFITS VERY LOW FORWARD VOLTAGE DROP FOR LESS POWER DISSIPATION AND REDUCED HEATSINK SIZE REVERSE VOLTAGE SUITED TO OR-ing OF 3V, 5V and 12V RAILS DESCRIPTION Packaged in TO-220AC or D2PAK, this device is especially intended for use as an OR-ing diode in fault tolerant power supply equipments. TO-220AC STPS20L15D A A K 20 A 15 V 125°C 0.33 V K K NC D2PAK STPS20L15G ABSOLUTE RATINGS (limiting values) Symbol VRRM IF(RMS) IF(AV) IFSM IRRM IRSM Tstg Tj dV/dt * : Parameter Repetitive peak reverse voltage RMS forward current Average forward current Surge non repetitive forward current Repetitive peak reverse current Non repetitive peak reverse current Storage tem [ ... ]

STPS20L15D PDF Datasheet Download