The last FIFA game officially released by EA Sports for the PlayStation Portable was . The PSP console was discontinued in 2014, and EA shifted its development resources entirely to the PS4, Xbox One, and PC platforms. Consequently, FIFA 17 was never ported to the PSP, meaning an "official" ISO file does not exist.
Use an extraction tool like (for Android) or WinRAR/7-Zip (for PC). Locate the downloaded archive in your downloads folder, open it, and extract its contents. The extraction will yield a file with a .ISO or .CSO extension, which is the game file the emulator reads. fifa 17 ppsspp iso file link
Set to 1x PSP for budget phones, or 2x PSP for mid-range devices to achieve sharper visuals without lagging. The last FIFA game officially released by EA