This part is a kind of semiconductor called BA08ST.

Function of this product has Regulator / low drop-out type with ON/OFF switch.

Manufacturers : Rohm

Image and pinout :

Some of the text within the PDF file :

Regulator ICs BAΟΟST / BAΟΟSFP series Regulator, low drop-out type with ON/OFF switch BAΟΟST / BAΟΟSFP series The BAΟΟST and BAΟΟSFP series are variable, fixed output low drop-out type voltage regulators with an ON/OFF switch. These regulators are used to provide a stabilized output voltage from a fluctuating DC input voltage. Fixed output voltages are 3.3V, 5V, 6V(SFP), 7V, 8V, 9V, 10V(ST), 12V(ST). The maximum current capacity is 1 A for each of the above voltages. !Application Constant voltage power supply !Features 1) Built-in overvoltage protection circuit, overcurrent protection circuit and thermal shutdown circuit 2) TO220FP-5, TO252-5 standard packages can be accomodated in wide application. 3) 0µA (design value) circuit current when switch is off 4) Richly diverse [ ... ]

BA08ST PDF Datasheet Download