We have started production using LPC54605/6 using 100 pin package. A number of the parts are latching up during initial power up - say 5-10 out of a few thousand. This causes the 3.3 volt regulator to go into current limiting mode. If you remove power from the board and reapply quickly before 3.3 volts has completely discharged the NXP will power up correctly. If you let the supply voltage completely discharge the NXP will latch up every time.
I have removed all voltages on the board excepting the 3.3V required by NXP - no difference.
Replacing the NXP processor fixes the issue 100% of time.
I have noted that NXP processors with issue appear to be from a more leaky corner of IC manufacturing process. Typical I/O pin resistance to ground on working units is 7meg ohm. The problematic processors are closer to 5meg ohm.
Given that leakage is also related to temperature I believe it will be possible to have processors pass initial testing during production only to have same problem during end customer power on.
We need to make decisions regarding production stop. Who can escalate this issue?