I have experienced failures of the LMZ14202 regulator with the output and input going short circuit. These failures happen in installed equipment but not in our lab.
The LMZ14202 is fed by a non-isolated DC/DC converter which produces 28V DC. This is well regulated and under transient conditions to the input of the DC/DC converter, the output fluctuates by no more than +/-4V. The schematic of the LMZ14202 is shown below. The output caps are ceramic but the input cap is electrolytic. Loading is less that 200mA on the output which is set to 5V. The input supply is fed via a shottky diode, to give some hold up during supply dips.
Is there anything obviously wrong here? Is the electrolytic cap a bad choice? Would a ceramic input cap be better?
Any suggestions would be welcome.
