Everything for Electronics

Tech Forum

2020 Issue-2

Protection Of Device Against Automotive Transients, Reverse Voltage

I was wondering what would be suggested to properly provide protection of a device with a 5V low power regulator and LED driver against automotive transients, and reverse voltage that is connected to an automotive starting battery.

I presume a TVS diode could be used, but should it be bi-directional or uni-directional? A Schottky diode could be used for low voltage drop, first in line for reverse voltage protection, but it would have to withstand the clamping current of the TVS diode.

Would it be be necessary to include a resettable fuse if the transient lasted too long and exceeds the power rating of the TVS diode?

Wayne Carpenter
Omak, WA

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