This part is a kind of semiconductor called T3055EL.

Function of this product has MMFT3055EL.

Manufacturers : Motorola

Image and pinout :

Some of the text within the PDF file :

MOTOROLA SEMICONDUCTOR TECHNICAL DATA Order this document by MMFT3055EL/D Medium Power Field Effect Transistor N–Channel Enhancement Mode Silicon Gate TMOS E–FETt SOT–223 for Surface Mount This advanced E–FET is a TMOS power MOSFET designed to withstand high energy in the avalanche and commutation modes. This device is also designed with a low threshold voltage so it is fully enhanced with 5 Volts. This new energy efficient device also offers a drain–to–source diode with a fast recovery time. Designed for low voltage, high speed switching applications in power supplies, converters and PWM motor controls, these devices are particularly well suited for bridge circuits where diode speed and commutating safe operating areas are critical and offer additional [ ... ]

T3055EL PDF Datasheet Download