Tektronix 2247A

fall
4
rh
Ey
geYy
Basic Applications
Propagation Delay
Propagatlon delay Is an automatic measurement of the time difference
between trigger events on two different channels. Use the setup for making
time-difference measurements as a guideline and select the PROPDLY
menu Item from the Time measurements menu. If desired, the trigger level
may be adjusted by selecting the B Trigger and adjusting the Trigger LEVEL
control.
Rise Time Measurements
Rise time and fall time measurements can be made automatically by
selecting the appropriate menu Item In the Time measurements menu. Use
the procedure for making time-difference measurements to get a stable
display on the Instrument. Then go to the RISE/FALL menu and select the
desired trigger level and select RISE. The Instrument will prompt you to
Increase the V/div level, If required, for It to make the automatic rise time
measurement.
Phase Measurements
Making a phase measurement Is done by first setting a reference for the full
360 degree waveform period. Use the following procedure as a guide.
1. Apply the reference waveform to the CH 1 input connector (any channel
may be used, but CH 1 and CH 2 provide the most signal-scaling pos-
sibilities). Use the standard 10X attenuator probe supplied with the
Instrument to make the signal connections as they produce very little
signal loading to a circult under test and produce matched delays. For
phase measurements, external loading of a circult and different delays
In the signal connection paths will produce Incorrect results.
2.
Select
CH
1
for
display
using
the
VERTICAL
MODE
buttons
and
set
the
Input
COUPLING
for
CH
1
and
CH
2
to
DC.
AC
may
be
used
If
the
signals
to
be
measured
are
riding
on
a
dc
voltage,
but
set
both
Inputs
to
the
same
coupling.
AC
coupling
produces
some
signal
phase
shift,
especially
at
lower
frequencies.
3. Set the CH 1 VOLTS/DIV control to display the reference waveform
with
about
five
divisions
of
amplitude.
Vertically
center
the
waveform.
4.
Set
the
A
SEC/DIV
setting
(in
A
Horizontal
MODE)
to
display
at
least
one
complete
reference
waveform
period
and
no
more
than two
(if
possible).
An
excessive
number
of
cycles
of
the
reference
waveform
In
2247A
Operators
5-11