Specifications

Standad
Measurements
User defined
Measurements
Whea
any of
the standard
Eeasurements
are requestd the
HP
54510A
first
determines
the topbase
voltage levels
attnVo-W%.
fvsrn
this
information,
it can
determiae
thresholds
(!0Vo,X)Vo,
andl0Vo)
needed
to
nake the measurements.
"I\el0Vo
and90%o
thresholds
are used in the
risetime
and falltime Deasurements. \\e
50Vo
nidpoint
is tsed for
measuring
frequency,
perio4 pulse
widt\
and
duty cycle.
The voltage
thresholds are
precise
settings
and sets specific
locations
on
the waveform.
If
the thresholds
are not
placed
on the
waveform
(above
or
below) the HP
54510A cannot
nake
a
measuremenL
When any
of the ussr defined
measurements
are
requeste4
the
HP
54510A still must
determine the
topbase
voltage thresholds.
From
this information it
can determine
user
defined
upper
and
lower
thresholds. Tbe mid-point is
then
determined
to
be
the 507o
point
between the upper
and
lower
tbreshold.
Automatic
Top-Base
A:9ortthms
A‐2
Top-Base
is
the heart of most automatic meiasurements.
It is
used to
determine V1qp
and Vuasc, the oVo andtffiVovoltage
levels
at the top and
the
bottom of the waveform. From
this
information
the oscilloscope can
determine
the
l0Vo,50Vo,
and90Vo
pornts,
which are also used in most
measurements.
The
top or base of the
waveform is not necessarily
the
maximum
s1
minimu
voltage
present
on thewaveform. Consider a
pulse
that
has
slight
overshoot.
It would
be
v/rong
to select
t[s
highssl
point
of
the waveform
as the top since the
waveform
normally
rests
below the
perturbation.
TopBase
performs
a
histogram
on the
waveform and finds
the most
prevalent point
above and below the
waveform
midpoint.
The
most
prevalent
point
is
one
that
represents
greater
than
approximately
5Vo of
the
total display
points
(501)
and is considered
to
be either
the top or
base. If
no point
accounts
for more than
5Vo of the
total, then the
top is
chosen as the
absolute maximum and the base
is chosen
as the absolute
minimum.
HP 54510A
F『
ont‐
Pane:Reference