Finally, the delayed breakdown device (DBD) is a small pn junction device which
is driven into reverse breakdown by a suitably high voltage and fast rise time pulse
in the 1–10 kV range [46]. If the overvoltage can be applied fast enough, i.e. in a
nanosecond timescale, the avalanche breakdown across the pn junction takes the form
of a plasma shock wave, and the current rise time through the device is much faster
than that of the applied voltage. The device acts as a pulse sharpener.