We followed the data sheet very closely on the layout, and it seems to work fine, with no noise on the output (< 10 mv p-p), but 4 out of 9 boards have a 2.5V regulator that has failed.
Now, we did have a problem with our solder paste mask, and did not originally have solder under the chip, but we had the board house remove the chips, add the paste, and resolder them before we powered them up. Could the extra soldering cycles have damaged the parts? And if that's the problem, why don't the 1.0 and 1.8V chips fail?
I can provide more information, like schematic and layout snapshots if you like. Any hints would be appreciated.
Probably the issue is not a soldering issue, so i would like to review the schematic and i need to have some waveforms for Vout, Enable and PVIN from a working 2.5V board for the startup and shutdown events.
I will send you an personal email so you can attache that information without exposing any confidential information.