This part is a kind of semiconductor called SP8K31.

Function of this product has 4V Drive Nch+Nch MOSFET.

Manufacturers : Rohm

Image and pinout :

Some of the text within the PDF file :

Transistor 4V Drive Nch+Nch MOSFET SP8K31 SP8K31 zStructure Silicon N-channel MOSFET zFeatures 1) Built-in G-S Protection Diode. 2) Small surface Mount Package (SOP8). zDimensions (Unit : mm) SOP8 zApplications Switching zPackaging dimensions Package Type Code Basic ordering unit (pieces) SP8K31 Taping TB 2500 zAbsolute maximum ratings (Ta=25°C) Parameter Symbol Drain-source voltage VDSS Gate-source voltage VGSS Drain current Continuous Pulsed ID IDP ∗1 Source current (Body diode) Continuous Pulsed Total power dissipation IS ISP ∗1 PD ∗2 Channel temperature Tch Range of storage temperature Tstg ∗1 Pw 10µs, Duty cycle 1% ∗2 Mounted on a ceramic board. Limits 60 ±20 ±3.5 ±14 1.0 14 2.0 150 −55 to + [ ... ]

SP8K31 PDF Datasheet Download