This part is a kind of semiconductor called SFH6156-3.

Function of this product has Optocoupler / High Reliability / 5300 VRMS.

Manufacturers : Vishay Siliconix

Image and pinout :

Some of the text within the PDF file :

VISHAY SFH615A / SFH6156 Vishay Semiconductors Optocoupler, High Reliability, 5300 VRMS Features • Excellent CTR Linearity Depending on Forward Current • Isolation Test Voltage, 5300 VRMS • Fast Switching Times • Low CTR Degradation • Low Coupling Capacitance • Lead-free component • Component in accordance to RoHS 2002/95/EC and WEEE 2002/96/EC 1 A 1 C 2 17448 4 3 C E 1 Agency Approvals • UL1577, File No. E52744 System Code H or J, Double Protection • DIN EN 60747-5-2 (VDE0884) DIN EN 60747-5-5 pending Available with Option 1 Order Information Part SFH615A-1 SFH615A-2 SFH615A-3 SFH615A-4 SFH6156-1 SFH6156-2 SFH6156-3 SFH6156-4 SFH615A-1X006 SFH615A-1X007 SFH615A-2X006 SFH615A-2X007 SFH615A-2X009 SFH615A-3X006 SFH615A-3X007 SFH615A-3X008 SFH615A-3X009 SFH615A-4X0 [ ... ]

SFH6156-3 PDF Datasheet Download