When entering 19V, ADM1270 occurs in the following three conditions.
ADM1270 => IC Burned (Burned after power on)
ADM1270 => IC Hot (Ic started hot)
ADM1270 => (Vcc=19V, Vcap no output.)
Is there a problem with the design?
Hello, Nathan's suggestions are good and worth investigating.
Please confirm that this happens during initial turn on approaching 19V. If not, then describe the exact failure mechanism. On top of that it would be helpful to determine if the MOSFETs that you are using survived power on. You mentioned that the IC gets hot, do the FETs also get hot?
The ADM1270 should only draw a few hundered microamps of bias current when powered through the SENSE+ pin, and this is not enough to burn up the IC. Your schematic looks reasonable (looks very much like the schematic for the ADM1270CP-EVALZ demo schematic), so that is probably not the problem.The most likely problem is that you are somehow incorrectly biasing one of the IC pins (probably applying 19V where it should not be).
I would suggest that you start by measuring the voltages at each of the IC pins, and try to determine where the problem voltage is coming in. My guess would be that you have a soldering defect that is shorting a pin to 19V, and once you remove the short circuit (and replace the damaged IC) everything will function correctly. After you have measured the pin voltages you should be able to narrow-down your search for board and soldering defects.