The basic strategy for overvoltage protection is to place a TVS device in parallel with the protected circuit. The TVS device is specifically designed to breakdown at a certain voltage level and conduct large amounts of current without sustaining damage. The challenge is to insure that the overvoltage protector will safely and quickly redirect the unwanted energy away from the protected circuit. An important concept is device turn-on time which needs to be fast enough to keep up with the overvoltage waveform rise time.

