- The time that elapses for a given amount of decay to occur. For example, the time it takes a static charge to be reduced to a given percentage of its peak charge. Also called decay time (1), or storage time (4).
- The time required for the amplitude of a pulse to decrease from a given percentage of its peak amplitude, such as 90%, to another, such as 10%. Also called pulse fall time, or decay time (2). rise time (2) is the converse.
- The time required for the output of a circuit to change from a high level, or 1, to a low level, or 0.