I am powering a PIC32MX microchip using a 3.3V Linear Regulator (LM2937), supplied from an RBO40 which I fitted in an effort to protect against adverse conditions such as load dump. As an aside, I've just ordered a Murata buck converter (RS-Online part 796-2141) to replace the linear regulator.
The PIC32MX is connected exactly as per the datasheet with the recommended capacitors within a few mm of the power supply pins.
The PCB is mounted inside my classic car and controls various systems such as PWM dimmed lights, gauges, switches etc etc. Whilst not safety critical it would be desirable if the PIC would remain running during engine start, which it doesn't (always resets). A breadboard-ed thru hole version of the PIC does continue running during engine start on my regular (modern) car, so I wondered if perhaps the classic has a more aggressive starter motor or alternator, or weaker battery that is contributing to this issue.
I'll try the buck converter instead and see if that's any different.
Otherwise should I consider any particular rating of bulk capacitor perhaps? Before or after the voltage regulator? I've googled the issue but not got anything definitive, just confusing myself. Thanks in advance.