I'm using Arduino Pro Micro (5v version) in one of my project for my car. The car's 12V +ve connected to RAW input of ProMicro and everything seems to work perfectly until I crank the ignition of my car. Here's what actually happened, my circuit works perfectly fine when car's ignition is in ON state. However, as soon as I started my car the voltage dropped from 12v to between 9-10volt and the LG33 (SMD voltage regulator) burned out. Now, I want a good solution as what should I do now? I have already LM2596 DC 3A Step-Down regulator. So should I use that to step-down 12v to 5v OR is there anything else I can do which might be a better solution?