Datasheet in PDF format numbered 6262, about 1.05 MB, with no part number or brand stated in the file name. The device it covers must be identified from the document itself. At this size it likely includes block diagrams, electrical tables and package drawings rather than a brief summary. Any PDF reader opens it. Use it to confirm pin assignments, supply rails and maximum ratings when testing or replacing a component, after checking that the chip marking on the board matches the documented part.
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 @datasheet. 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.