The absolute maximum rated voltage is a voltage that must not be exceeded even instantaneously.
However, today's applications generate brief spikes exceeding the absolute maximum rated voltage at power-up. For these applications, the avalanche resistance may be used as a limiting parameter instead of the absolute maximum rated voltage.
The avalanche capability can only be applied when 1) the absolute maximum rated voltage is exceeded only at power-up (and is never exceeded during steady-state operation), and 2) the avalanche current is lower than the absolute maximum rated current. The avalanche capability is derated for channel temperature.
The scope of use of the avalanche capability varies from device to device. For details, contact your local Toshiba sales representative.