This part is a kind of semiconductor called AOD4185.

Function of this product has P-Channel Enhancement Mode Field Effect Transistor.

Manufacturers : Alpha & Omega Semiconductors

Image and pinout :

Some of the text within the PDF file :

AOD4185/AOI4185 P-Channel Enhancement Mode Field Effect Transistor General Description The AOD4185/AOI4185 uses advanced trench technology to provide excellent RDS(ON) and low gate charge. With the excellent thermal resistance of the DPAK/IPAK package, this device is well suited for high current applications. -RoHS Compliant -Halogen Free* TO252 DPAK Top View D D D G S G S G G D S S D G S Bottom View Top View D Features VDS (V) = -40V ID = -40A (VGS = -10V) RDS(ON) < 15mΩ (VGS = -10V) RDS(ON) < 20mΩ (VGS = -4.5V) 100% UIS Tested! 100% Rg Tested! TO-251A IPAK Bottom View D Absolute Maximum Ratings TC=25° C unless otherwise noted Parameter Symbol Drain-Source Voltage VDS Gate-Source Voltage Continuous Drain Current B,H Pulsed Drain Current Avalanche Current C Repetitive avalanche en [ ... ]

AOD4185 PDF Datasheet Download