Tektronix PG 508, Инструкция по эксплуатации

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TM 11-6625-2980-14
Definitions of Pulse Characteristics The following
is a glossary of common pulse characteristics used in
this manual. They are illustrated in Fig. 1-8.
Amplitude. The maximum absolute peak value of a
pulse measured from the baseline regardless of sign,
and excluding unwanted aberrations or overshoot.
Measurement points are at 50% of the pulse duration
time (pulse high level) and on the baseline (pulse low
level) at 50% of the off time (the pulse period minus the
pulse duration).
Aberrations. Unwanted deviations or excursions in
the pulse shape form an ideal square corner and flat
top, i.e., overshoot, undershoot or rounding, ringing, and
tilt or slope.
Baseline. The quiescent dc voltage reference level
of the pulse waveform.
Complementary Pulse. Normal pulse with high and
low levels interchanged. Pulse on-time becomes pulse
off time.
Duty Factor. Sometimes referred to as duty cycle.
The ratio of pulse duration to period, or the product of
pulse duration and pulse repetition rate. Duty factor in %
=Duration/Period X 100.
Falltime. The time interval, at the pulse trailing
edge, for the pulse amplitude to fall from the 90%
amplitude level to the 10% amplitude level.
Flatness. The absence of long term variations to
the pulse top; excluding overshoot, ringing or pulse
rounding. Sometimes referred to as tilt or slope.
High Level. The most positive value of a pulse,
regardless of unwanted aberrations or overshoot,
measured at a point that is located at 50% of the pulse
duration.
Low Level. The most negative value of a pulse,
regardless of unwanted aberrations or overshoot,
measured at a point that is 50% of the off time.
Offset. A dc potential of either polarity applied to
the waveform to bias the baseline to an amplitude other
than zero
Overshoot. The short term pulse excursion (or
transient) above the pulse top or below the baseline,
which is simultaneous to the leading or trailing edge of
the pulse.
Period. The time interval for a full pulse cycle,
inverse of frequency or repetition rate, or the interval
between corresponding pulse amplitudes of two
consecutive undelayed or delayed pulses. Generally
measured between the 50% amplitude levels of two
consecutive pulses.
Preshoot. A transient excursion that precedes the
step function. It may be of the same or opposite polarity
as the pulse.
Fig . 1-8 . Pulse characteristics .
1-8