This part is a kind of semiconductor called A556RW.

Function of this product has 5W Single & Dual Output DC/DC Converters.

Manufacturers : MicroPower Direct

Image and pinout :

Some of the text within the PDF file :

A500RW Series Wide Input Range, 5W Single & Dual Output DC/DC Converters Electrical Specifications Specifications typical @ +25°C, nominal input voltage & rated output current, unless otherwise noted. Specifications subject to change without notice. Key Features: • 5W Output Power • EN 60950 Approved (UL) • 2:1 Input Voltage Range • 1,500 VDC Isolation • Meets EN55022 Class “A” • Compact DIP Case • Single & Dual Outputs • 1.0 MH MTBF • Industry Standard Pin-Out Input Parameter Input Start Voltage Input Filter Reverse Polarity Input Current Short Circuit Input Power Output Parameter Output Voltage Accuracy Output Voltage Balance Line Regulation Load Regulation Ripple & Noise (20 MHz) Ripple & Noise (20 MHz) Ripple & Noise (20 MHz) Output Power Protection Transien [ ... ]

A556RW PDF Datasheet Download