This part is a kind of semiconductor called STPS20L15D.

Function of this product has SCHOTTKY RECTIFIER.

Manufacturers : International Rectifier

Image and pinout :

Some of the text within the PDF file :

Bulletin PD-20627 rev. C 06/06 STPS20L15D STPS20L15G SCHOTTKY RECTIFIER 20 Amps IF(AV) = 20Amp VR = 15V Major Ratings and Characteristics Characteristics IF(AV) Rectangular waveform VRRM IFSM @ tp = 5 μs sine VF TJ @ 19 Apk, TJ=125°C ( Typical) range Description/Features Units A V A V The Schottky rectifier module has been optimized for ultra low forward voltage drop specifically for the OR-ing of parallel power supplies. The proprietary barrier technology allows for reliable operation up to 125 °C junction temperature. Typical applications are in parallel switching power supplies, converters, reverse battery protection, and redundant power subsystems. 125°C TJ operation (VR < 5V) Center tap module Optimized for OR-ing applications Ultra low forward voltage drop H [ ... ]

STPS20L15D PDF Datasheet Download