Hello Kiran

The electric wiring in a vehicle is one of the most hostile places for electronics.
You got all sorts of electric noise from the ignition, and problems with voltage regulation and the load dump effect. Say you switches off some heavy load (40 - 60A). Due to poor regulation the voltage will raise to maybe 80V in short peeks.

This paper: www.everyspec.com/MIL-STD/MIL-STD+(1100+-+1299)/download.php?spec=MIL-STD-1275D.00001072.pdf will give some details of what to allow or expect in a (military) vehicle.
As a bare minimum you could try with a large tranzorb. A ST BZW50-33B could do the job.

I think, that I, in your shoes, would tell sales, that the product isn’t made for automotive use, and that you won't accept that its sold for that purpose. What the end customer do against the manufacturers advice is his/her own problem.

If sales think there is a market you could do a new device, targeted for automotive use.

That includes a power supply accepting peakinput voltage spikes at 60V or 80V DC, and the micro, inputs, output etc. suited for the environment. Don’t forget the often very high ambient temperature in your calculations.


Per