The peak pulse current is the maximum current the protection device can withstand. It has a wave shape that is derived from standards pertaining to lightning immunity and also an important aspect for devices that are mostly geared towards protecting telecom equipment from induced lightning surges. Often TVS diode array datasheets will show current levels with a wave shape following them such as 8 by 20 or 2 by 10. This is simply stating the rise time and fall time to 50% of it’s peak as shown in the plot to the left. These are also the same currents used to test for clamping voltage because the longer µs rise times help avoid issues with parasitic inductance.