Datasheet-style schematic data in PDF for the Texas Instruments TPS51488, ordering code TPS51488RJER, a small 81.6 KB document. It typically includes the reference circuit, pin functions and application notes for the controller. Technicians consult it to check expected pin voltages, enable and power-good signals and external component values when a regulator on a laptop board fails to start. Compare the marking code on the chip with the part number before relying on the pinout, since package variants can differ.
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 @THE_BIOS_WORLD. 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.