Review overvoltage protection on power circuit

Projects General Guidance
7

The "basic" input conditions an electronic automotive part must survive is: ( these are a crude summary of the various OEM specifications).

  1. Load dump, Max 50V decaying to "nominal" voltage in < 400 ms
  2. Double battery jump start: Couple of minutes at 24V.
  3. Reverse voltage
  4. Various short high voltage spikes
  5. ESD.

Usually a 0.1µF capacitor right at the board input is adequate for the high voltage spikes and ESD assuming 1,2,&3 are met.