Datasheet for the Richtek RT8105 in PDF form, roughly 206 KB. The file name gives only the part number, with no revision or package variant. Richtek controllers of this family appear in the power circuitry of motherboards and graphics cards, and the sheet is used to identify the pin functions, enable and feedback pins, and typical application circuit while measuring a rail that will not come up. Verify the top marking on the chip, since Richtek parts often use short marking codes rather than the full name.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @ic_mosfet_pdf_datasheets. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.