This part is a kind of semiconductor called 78D08L.

Function of this product has 3-TERMINALS 0.5A POSITIVE VOLTAGE REGULATOR.

Manufacturers : Unisonic Technologies

Image and pinout :

Some of the text within the PDF file :

UNISONIC TECHNOLOGIES CO., LTD 78DXXL LINEAR INTEGRATED CIRCUIT 3-TERMINALS 0.5A POSITIVE VOLTAGE REGULATOR  DESCRIPTION The UTC 78DXXL family is monolithic fixed voltage regulator integrated circuit. They are suitable for applications that required supply current up to 0.5 A.  FEATURE * Output Current Up To 0.5 A * Fixed Output Voltage Of 5V, 6V, 8V, 9V, 12V, 15V and 18V Available * Thermal Overload Shutdown Protection * Short Circuit Current Limiting * Output Transistor SOA Protection  ORDERING INFORMATION Ordering Number Lead Free Halogen Free - 78DXXLG-AA3-R - 78DXXLG-AB3-B-R 78DXXLL-TM3-T 78DXXLG-TM3-T 78DXXLL-TN3-R 78DXXLG-TN3-R 78DXXLL-TNA-R 78DXXLG-TNA-R Note: 1. XX: Output Voltage, refer to Marking Information 2. Pin Code: I: Input G: GND O: Output Pack [ ... ]

78D08L PDF Datasheet Download