A nonrepetitive waveform that rises or falls exponentially from some initial value at some initial time, according to the law
For
a > 0 the waveform rises without bound with increasing time
t; for
a < 0 the waveform decays to zero. One way in which logic signals can become distorted as they travel through a system is for their switching edges to become exponentials, usually due to capacitive loading when the output waveform follows the law
where
V is the final voltage,
R the source resistance, and
C the capacitive load.