HP 54750A, User Manual, Page: 201 / 478

W aveform Measurements
The Waveform Measurement Process
Determining rising and falling edges
The nal analysis needed to make timing measurements is to dene the
transition points of the waveform through the threshold levels and to dene
the rising and falling edges . A rising edge is dened as a transition that
passes through the lower , middle , and upper threshold levels . A falling edge
is dened as a transition that passes through the upper , middle , and lower
threshold levels . F or an edge to be present and dened, it must complete the
transition through all three threshold levels .
Once the transition points and edges are identied, the instrument next
calculates timing measurements (rise time , fall time , and frequency). Finally ,
it calculates voltage measurements that need timing information (Vrms cycle
and V avg cycle) as shown in Figure 7-6 .
Figure 7-6. Thresholds are used to determine edges.
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