This part is a kind of semiconductor called ADD1021.
Function of this product has Power Line Communications System.
Manufacturers : ADD Semiconductor
Image and pinout :
Some of the text within the PDF file :
ADD1021 Datasheet Doc Rev 1.04 Datasheet — 25-May-2010 Document information Info Author Keywords Abstract Content J.G. 1021, Datasheet ADD Semiconductor Revision History Revision 1.02 1.03 1.04 Date 2010-03-29 2010-04-08 2010-05-25 Description --Updated example circuit Max output current values updated ADD1021 Datasheet Author J.G. J.G. J.G. Copyright: © 2010 ADD Semiconductor. All rights reserved. ADD Semiconductor does not warrant nor represent that any license, either expressed or implied is granted under any ADD Semiconductor patent right, copyright, mask work right or other ADD Semiconductor intellectual property right relating to any combination, machine or process in which ADD Semiconductor product and services are used. Information published by ADD Semiconductor [ ... ]