LO turns on when HS detects a
slew rate change from high to low (During a switching transition, the slew rate
rises up first and then drops back to zero) – indicating HS voltage reaches the
minimal value. So, the dead time from HO to LO is automatically adjusted based
on HS voltage.
Minimal detectable slew rate is
0.1 V/ns (check when HS at 20 V).
Dead time from LO to HO is copied
from the previous HO to LO switching.