HP 54540 Series - Determining Rising and Falling Edges

Figure 13-6
Measurements
Determining Rising and Falling Edges
Determining Rising and Falling Edges
The final analysis needed to make timing measurements is to define the
transition points of the waveform through the threshold levels and to define
the rising and falling edges. A rising edge is defined as a transition that
passes through the lower, middle, and upper threshold levels. A falling edge
is defined as a transition that passes through the upper, middle, and lower
threshold levels. For an edge to be present and defined, it must. complete the
transition through all three threshold levels.
Once the transition points and edges are identified, the instrument next
calculates timing measurements (rise time, fall time, and frequency). Finally,
it calculates voltage measurements that need timing information (Vrms cycle
and Vavg cycle) as shown in figure 13-6.
a histogram
data In] build owes
edge[2] histogram,
edge[1] 1 top
ase
edgelO}
max (
top ee
min,max,mid
base
top,base,clip
min _ &
i
edge
array
ae
.
‘
Vin,
Vmax,Vpp
edge
coun
find
_Vbase,Vtop.
Vamp
_
Tmeas:
edge
risetime,freq
falltime,period
Vmeas:
Vavg Vrms
10%,50%,90%
Thresholds are used to determine edges
13-9