Runt trigger

Another unique criterion in the timing mode is the “runt trigger.” In digital logic families, two thresholds are used to discriminate between logic ones and logic zeros. A “zero” is defined to be less than 0.8 V, and a “one” is greater than 2.0 V. The middle region between 0.8 and 2.0 V is the switching zone used to improve noise margin. A runt pulse crosses one threshold, but not the other. Figure 29.20 shows an example waveform for a runt pulse.