IEC 60469:2013

IEC 60469 ®
Edition 1.0 2013-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Transitions, pulses and related waveforms – Terms, definitions and algorithms

Transitions, impulsions et formes d'ondes associées – Termes, définitions et
algorithmes
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IEC 60469 ®
Edition 1.0 2013-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Transitions, pulses and related waveforms – Terms, definitions and algorithms

Transitions, impulsions et formes d'ondes associées – Termes, définitions et

algorithmes
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XB
ICS 01.040.17; 17.220.20 ISBN 978-2-83220-747-5

– 2 – 60469 © IEC:2013
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and symbols . 7
3.1 General . 7
3.2 Terms and definitions . 7
3.3 Symbols . 25
3.4 Deprecated terms . 25
4 Measurement and analysis techniques . 26
4.1 General . 26
4.2 Method of waveform measurement . 26
4.3 Description of the waveform measurement process . 27
4.4 Waveform epoch determination . 28
4.4.1 Selection of waveform epoch . 28
4.4.2 Exclusion of data from analysis . 28
Analysis algorithms for waveforms . 28
5.1 Overview and guidance . 28
5.2 Selecting state levels . 28
5.2.1 General . 28
5.2.2 Data-distribution-based methods - Histograms. 28
5.2.3 Data-distribution-based methods - Shorth estimator . 31
5.2.4 Other methods . 33
5.2.5 Algorithm switching. 34
5.3 Determination of other single transition waveform parameters . 34
5.3.1 General . 34
5.3.2 Algorithm for calculating signed waveform amplitude . 34
5.3.3 Algorithm for calculating percent reference levels . 35
5.3.4 Algorithms for calculating reference level instants . 35
5.3.5 Algorithm for calculating transition duration between x1 % and x2 %
reference levels . 36
5.3.6 Algorithm for calculating the undershoot and overshoot aberrations of
step-like waveforms . 36
5.3.7 Algorithm for calculating waveform aberrations . 38
5.3.8 Algorithm for calculating transition settling duration . 39
5.3.9 Algorithm for calculating transition settling error . 40
5.4 Analysis of single and repetitive pulse waveforms . 40
5.4.1 General . 40
5.4.2 Algorithm for calculating pulse duration . 40
5.4.3 Algorithm for calculating waveform period. 40
5.4.4 Algorithm for calculating pulse separation . 41
5.4.5 Algorithm for calculating duty factor . 42
5.5 Analysis of compound waveforms . 42
5.5.1 General . 42
5.5.2 Waveform parsing . 43
5.5.3 Subepoch classification . 45
5.5.4 Waveform reconstitution . 45

60469 © IEC:2013 – 3 –
5.6 Analysis of impulse-like waveforms . 46
5.6.1 Algorithm for calculating the impulse amplitude . 46
5.6.2 Algorithm for calculating impulse center instant . 46
5.7 Analysis of time relationships between different waveforms . 46
5.7.1 General . 46
5.7.2 Algorithm for calculating delay between different waveforms . 46
5.8 Analysis of waveform aberration . 46
5.9 Analysis of fluctuation and jitter . 46
5.9.1 General . 46
5.9.2 Determining standard deviations . 47
5.9.3 Measuring fluctuation and jitter of an instrument . 50
5.9.4 Measuring fluctuation and jitter of a signal source . 53
Annex A (informative) Waveform examples . 54
Bibliography . 64

Figure 1 – Single positive-going transition. 10
Figure 2 – Single negative-going transition . 11
Figure 3 – Single positive pulse waveform . 13
Figure 4 – Single negative pulse waveform . 13
Figure 5 – Overshoot and undershoot in single positive-going transition . 15
Figure 6 – Overshoot and undershoot in a single negative-going transition . 15
Figure 7 – Pulse train . 17
Figure 8 – Compound waveform . 22
Figure 9 – Calculation of waveform aberration . 23
Figure 10 – Waveform acquisition and measurement process . 27
Figure 11 – Generation of a compound waveform . 43
Figure A.1 – Step-like waveform . 54
Figure A.2 – Linear transition waveform . 55
Figure A.3 – Exponential waveform . 56
Figure A.4 – Impulse-like waveform . 57
Figure A.5 – Rectangular pulse waveform . 58
Figure A.6 – Trapezoidal pulse waveform . 59
Figure A.7 – Triangular pulse waveform . 60
Figure A.8 – Exponential pulse waveform . 61
Figure A.9 – Double pulse waveform . 62
Figure A.10 – Bipolar pulse waveform . 62
Figure A.11 – Staircase waveform . 63
Figure A.12 – Pulse train . 63

Table 1 – Comparison of the results from the exact and approximate formulas for
computing the standard deviation of the calculated standard deviations . 49

– 4 – 60469 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TRANSITIONS, PULSES AND RELATED WAVEFORMS –
TERMS, DEFINITIONS AND ALGORITHMS

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization
comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to
promote international co-operation on all questions concerning standardization in the electrical and electronic
fields. To this end and in addition to other activities, IEC publishes International Standards, Technical
Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to
as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee
interested in the subject dealt with may participate in this preparatory work. International, governmental and
non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates
closely with the International Organization for Standardization (ISO) in accordance with conditions determined
by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has
representation from all interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated
in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage
or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60469 has been prepared by IEC technical committee 85:
Measuring equipment for electrical and electromagnetic quantities.
This first edition of IEC 60469 cancels and replaces the second edition of IEC 60469-1 and
the second edition of IEC 60469-2, both published in 1987. It constitutes a technical revision.
This first edition of IEC 60469:
• combines the contents of IEC 60469-1:1987 and IEC 60469-2:1987;
• updates terminology;
• adds algorithms for computing values of pulse parameters;
• adds a newly-developed method for computing state levels.
The text of this standard is based on the following documents:
CDV Report on voting
85/409/CDV 85/433/RVC
60469 © IEC:2013 – 5 –
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
All terms defined in Clause 3 are italicized in this document.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – 60469 © IEC:2013
INTRODUCTION
The purpose of this standard is to facilitate accurate and precise communication concerning
parameters of transition, pulse, and related waveforms and to establish the techniques and
procedures for measuring them. Because of the broad applicability of electrical pulse
technology in the electronics industries (such as computer, telecommunication, and test
instrumentation industries), the development of unambiguous definitions for pulse terms and
the presentation of methods and/or algorithms for their calculation is important for
communication between manufacturers and consumers within the electronics industry. The
availability of standard terms, definitions, and methods for their computation helps improve
the quality of products and helps the consumer better compare the performance of different
products. Improvements to digital waveform recorders (including oscilloscopes) have
facilitated the capture, sharing, and processing of waveforms. Frequently these waveform
recorders have the ability to process the waveform internally and provide pulse parameters.
This process is done automatically and without operator intervention. This standard can be
applied in many more scientific and engineering applications than mentioned above, such as
optics, cosmology, seismology, medicine, etc., and ranging from single events to highly
repetitive signals and from signals with bandwidths less than 1 Hz to those exceeding 1 THz.
Consequently, a standard is needed to ensure that the definitions and methods of
computation for pulse parameters are consistent.
IEC 60469-1 dealt with terms and definitions for describing waveform parameters and
IEC 60469-2 described the waveform measurement process. The purpose of this standard is
to combine the contents of IEC 60469-1 and IEC 60469-2, update terminology, correct errors,
add algorithms for computing values of pulse parameters, and add a newly-developed method
for computing state levels. This standard reflects two major changes compared to
IEC 60469-1 and IEC 60469-2, which are the parameter definitions and algorithms. Changes
to the definitions included adding new terms and definitions, deleting unused terms and
definitions, expanding the list of deprecated terms, and updating and modifying existing
definitions. This standard contains definitions for approximately 100 terms commonly used to
describe the waveform measurement and analysis process and waveform parameters. Many
of the terms in standards IEC 60469-1 and IEC 60469-2 have been deleted entirely or
deprecated. Deprecated terms were kept in this standard to provide continuity between this
standard and IEC 60469-1 and IEC 60469-2. Terms are deprecated whenever they cannot be
defined unambiguously or precisely. Development of a set of agreed-upon terms and
definitions presented the greatest difficulty because of the pervasive misuse,
misrepresentation, and misunderstanding of terms. Legacy issues for instrumentation
manufacturers and terms of common use also had to be addressed. This standard also
resulted in the development of algorithms for computing the values of certain waveform
parameters in all cases where these algorithms could be useful or instructive to the user of
the standard. The purpose of adding these algorithms, which are recommended for use, was
to provide industry with a common and communicable reference for these parameters and
their computation. Heretofore, this was not available and there existed much debate and
misunderstanding between various groups measuring the same parameters. Similarly, this is
the reason for including several examples of basic waveforms, with formulae, in Annex A. The
algorithms focus on the analysis of two-state, single-transition waveforms. The analysis of
compound waveforms (waveforms with two or more states and/or two or more transitions) is
accomplished by first decomposing the compound waveform into its constituent two-state
single-transition waveforms. A method for performing this decomposition is provided.
Algorithms for the analysis of fluctuation and random jitter of waveforms were also introduced
into this standard. These algorithms describe the computation of the mean and standard
deviation of jitter and fluctuation. This standard also contains methods to estimate the
accuracy of the standard deviation and to correct its value.

60469 © IEC:2013 – 7 –
TRANSITIONS, PULSES AND RELATED WAVEFORMS –
TERMS, DEFINITIONS AND ALGORITHMS

1 Scope
This International Standard provides definitions of terms pertaining to transitions, pulses, and
related waveforms and provides definitions and descriptions of techniques and procedures for
measuring their parameters. The waveforms considered in this standard are those that make
a number of transitions and that remain relatively constant in the time intervals between
transitions. Signals and their waveforms for which this standard apply include but are not
limited to those used in: digital communications, data communications, and computing;
studies of transient biological, cosmological, and physical events; and electrical, chemical,
and thermal pulses encountered and used in a variety of industrial, commercial, and
consumer applications.
This standard does not apply to sinusoidally-varying or other continuously-varying signals and
their waveforms.
The object of this standard is to facilitate accurate and precise communication concerning
parameters of transitions, pulses, and related waveforms and the techniques and procedures
for measuring them.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
None.
3 Terms, definitions and symbols
3.1 General
Along with the recommended terms and their definitions, this clause also contains a number
of deprecated but widely used terms. These deprecated terms and the reason for their
deprecation are given after the definition of the recommended term.
Throughout this standard, time is taken to be an independent variable, symbolized with the
letter t. "Waveform value" is used to refer to the dependent variable, symbolized by y(t). For
particular waveforms, "waveform value" will be synonymous with terms such as "voltage",
"current", "power", or some other quantity. All defined terms are italicized in this document.
3.2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

– 8 – 60469 © IEC:2013
3.2.1
aberration region
3.2.1.1
post-transition aberration region
interval between a user-specified instant and a fixed instant, where the fixed instant is the first
sampling instant succeeding the 50 % reference level instant for which the corresponding
waveform value is within the state boundaries of the state succeeding the 50 % reference
level instant
Note 1 to entry: The user-specified instant occurs after the fixed instant and is typically equal to the fixed instant
plus three times the transition duration.
3.2.1.2
pre-transition aberration region
interval between a user-specified instant and a fixed instant, where the fixed instant is the first
sampling instant preceding the 50 % reference level instant for which the corresponding
waveform value is within the state boundaries of the state preceding the 50 % reference level
instant.
Note 1 to entry: The user-specified instant occurs before the fixed instant and is typically equal to the fixed instant
minus three times the transition duration.
3.2.2
accuracy
closeness of agreement between a measured quantity value and a true quantity value of a
measurand
[ISO/IEC Guide 99:2007, 2.13]
3.2.3
amplitude
3.2.3.1
impulse amplitude
difference between the specified level corresponding to the maximum peak (minimum peak) of
the positive (negative) impulse-like waveform and the level of the state preceding the first
transition of that impulse-like waveform
3.2.3.2
waveform amplitude
difference between the levels of two different states of a waveform
Note 1 to entry: Two different definitions for amplitude are authorized by this standard because they are both in
common use (see 3.2.3.2.1. In all applications of this standard, the chosen definition shall be clearly identified.:
3.2.3.3
signed waveform amplitude,
level of the state succeeding a transition minus the level of the state preceding the same
transition
3.2.3.4
unsigned waveform amplitude
absolute value of the signed amplitude
3.2.4
correction
operation combining the results of the conversion operation with the transfer function
information to yield a waveform that is a more accurate representation of the signal

60469 © IEC:2013 – 9 –
Note 1 to entry: Correction may be effected by a manual process by an operator, a computational process, or a
compensating device or apparatus. Correction shall be performed to an accuracy that is consistent with the overall
accuracy desired in the waveform measurement process.
Note 2 to entry: See 4.2 concerning the conversion operation.
3.2.5
cycle
portion of a periodic waveform with a duration of one period
3.2.6
delaying
process in which the time of arrival of a signal is caused to occur later in time
3.2.7
differentiation
shaping process in which a waveform is converted to a waveform whose shape is or
approximates the time derivative of that waveform
3.2.8
duration
difference between two specified instants
3.2.9
duty factor
DEPRECATED: duty cycle
unless otherwise specified, for a periodic pulse train, the ratio of the pulse duration to the
waveform period
Note 1 to entry: The term duty cycle is a deprecated term because the word cycle in this standard refers to the
period of a signal.
3.2.10
fluctuation
variation (dispersion) of a level parameter of a set of repetitive waveforms with respect to a
reference amplitude or a reference level
Note 1 to entry: Unless otherwise specified by a mathematical adjective, root-mean-square (rms) fluctuation is
assumed.
3.2.11
frequency
reciprocal of the period
Note 1 to entry: The period is the waveform period.
[IEC 60050-103:2009, 103-06-02, modified – the note to entry has been replaced.]
3.2.12
glitch
transient that leaves an initial state, enters the boundaries of another state for a duration less
than the duration for state occurrence, and then returns to the initial state
3.2.13
instant
particular time value within a waveform epoch that, unless otherwise specified, is referenced
relative to the initial instant of that waveform epoch
3.2.13.1
final instant
last sample instant in the waveform

– 10 – 60469 © IEC:2013
3.2.13.2
impulse center instant
instant at which a user-specified approximation to the maximum peak (minimum peak) of the
positive (negative) impulse-like waveform occurs
3.2.13.3
initial instant
first sample instant in the waveform
3.2.13.4
pulse center instant
average of the two instants used to calculate the pulse duration
3.2.13.5
reference level instant
instant at which the waveform intersects a specified reference level
3.2.13.6
transition occurrence instant
first 50 % reference level instant, unless otherwise specified, on the transition of a step-like
waveform
SEE: Figure 1, Figure 2, Figure 3, and Figure 4.

10 % level reference instant
50 % level reference instant
90 % level reference instant
s
!
90 % reference level
Waveform
!
50 % reference level
amplitude
! 10 % reference level
s
Transition occurrence instant
Offset
Transition duration
Base state
Waveform epoch
t
IEC  852/13
Figure 1 – Single positive-going transition

60469 © IEC:2013 – 11 –
90 % level reference instant
50 % level reference instant
10 % level reference instant
s
!
90 % reference level
Waveform
!
50 % reference level
amplitude
!
10 % reference level
s
Transition occurrence instant
Offset
Transition duration
Base state
Waveform epoch
t
IEC  853/13
Figure 2 – Single negative-going transition
Note 1 to entry: See 5.3.4 concerning reference level instants.
3.2.14
integration
shaping process in which a waveform is converted to a waveform whose shape is or
approximates the time integral of that waveform
3.2.15
interval
set of all values of time between a first instant and a second instant, where the second instant
is later in time than the first.
Note 1 to entry: These first and second instants are called the endpoints of the interval. The endpoints, unless
otherwise specified, are assumed to be part of the interval.
3.2.16
jitter
variation (dispersion) of a time parameter between successive cycles of a repetitive signal
and/or between successively acquired waveforms of a repetitive signal for a given reference
level instant or duration.
Note 1 to entry: Unless otherwise specified by a mathematical adjective, rms jitter is assumed.
3.2.16.1
th
-cycle jitter
cycle-to-n
jitter between specified reference level instants of any two specified cycles of a repetitive
signal
3.2.16.2
period jitter
jitter in the period of a repetitive signal or its waveform
3.2.16.3
pulse duration jitter
jitter in the pulse duration of a signal or its waveform

– 12 – 60469 © IEC:2013
3.2.16.4
trigger jitter
jitter between a repetitive signal and the trigger event that is used to generate or measure that
signal
3.2.17
level
constant value having the same units as y
3.2.17.1
average level
pertaining to the value of the mean of the waveform level
If the waveform takes on n discrete values y , all equally spaced in time, the average level is,
j
n
 
y=  y .
∑
j
 
n
j=1
If the waveform is a continuous function of time y(t),
t
 
y=  y(t)dt.
∫
 t − t 
2 1 t
Note 1 to entry: The summation or integral extends over the waveform epoch for which the average level is desired
or, if the function is periodic, over any integral number of periodic repetitions of the function.
3.2.17.2
average absolute level
pertaining to the mean of the absolute waveform value
If the waveform takes on n discrete values y , all equally spaced in time, the average absolute
j
level is,
n
 
y =  y .
∑
j
 
n
j=1
If the waveform is a continuous function of time y(t),
t
 
( )
y =  y t dt.
∫
 t − t 
2 1
t
Note 1 to entry: The summation or the integral extends over the waveform epoch for which the average absolute
level is desired or, if the function is periodic, over any integral number of periodic repetitions of the function.
3.2.17.3
percent reference level
reference level specified by:
x
y = y + y − y ,
( )
x% 0% 100% 0%
where
0 % < x < 100 %
y = level of low state
0 %
60469 © IEC:2013 – 13 –
y = level of high state
100 %
y , y , and y are all in the same unit of measurement.
0 % 100 % x %
SEE: Figure 1, Figure 2, Figure3, and Figure 4.
Note 1 to entry: Commonly used reference levels are: 0 %, 10 % , 50 %, 90 %, and 100 %.

Pulse center instant
s
! !
90 % reference level
Waveform
! !
amplitude
50 % reference level
Pulse duration
! !
10 % reference level
s
First transition
Offset
ocurrence instant
First transition duration
Second transition duration
Second transition occurrence instant
Base state
Waveform epoch
t
IEC  854/13
Figure 3 – Single positive pulse waveform

First transition duration Second transition duration
s2
! !
90 % reference level
Pulse duration
Waveform
amplitude ! !
50 % reference level
! !
10 % reference level
s
Pulse center instant
First transition
Offset
occurrence instant
Second transition occurrence instant
Base state
Waveform epoch
t
IEC  855/13
Figure 4 – Single negative pulse waveform
3.2.17.4
reference level
DEPRECATED: mesial, proximal, distal
user specified level that extends through all instants of the waveform epoch
Note 1 to entry: Mesial, proximal, and distal lines are deprecated terms because

– 14 – 60469 © IEC:2013
(a) line refers to consideration of and computations using a pictorial waveform representation, whereas
waveforms today are primarily stored in digital waveform representations and computation and viewing are
done using a computer;
(b) the terms mesial, proximal, and distal refer to user-defined reference levels and it is not necessary to have
redundant definitions for these reference levels;
(c) the terms proximal and distal cannot be used unambiguously to describe lines or points on either side of a
transition of a step-like waveform because they depend on whether the step-like waveform is for a positive
pulse or a negative pulse. In other words, for (3), the proximal line and points if referenced to the 10 %
reference level will appear to the left of a transition for a positive pulse and to the right for a negative pulse.
3.2.17.5
root-mean-square (rms) level
pertaining to the value of the square root of the average of the squares of the waveform
values
, all equally spaced in time, the root-mean-square
If the waveform takes on n discrete values y
j
level is,
n
 
y =   y .
∑
rms j
 
n
j=1
If the waveform is a continuous function of time y(t),
t
 
  ( )
y = y t dt .
rms ∫
 t − t 
2 1
t
The summation or the integral extends over the waveform epoch for which the rms level is
desired or, if the function is periodic, over any integral number of periodic repetitions of the
function.
3.2.17.6
root sum of squares level
rss level
pertaining to the value of the square root of the arithmetic sum of the squares of the waveform
values
If the waveform takes on n discrete values y , all equally spaced in time, the root sum of
j
squares level is,
n
y = y .
∑
rss j
j=1
If the waveform is a continuous function of time y(t),
t
( )
y = y t dt.
rss
∫
t
Note 1 to entry: The summation or the integral extends over the waveform epoch for which the root sum of squares
level is desired.
3.2.18
offset
algebraic difference between two specified levels.
SEE: Figure 1, Figure 2, Figure 3, and Figure 4.
Note 1 to entry: Unless otherwise specified, the two levels are state 1 and the base state.

60469 © IEC:2013 – 15 –
3.2.19
overshoot
waveform aberration within a post-transition aberration region or pre-transition aberration
region that is greater than the upper state boundary for the associated state level
SEE: Figure 5 and Figure 6.
Note 1 to entry: If more than one such waveform aberration exists, the one with the largest magnitude is the
overshoot unless otherwise specified.

Post-transition overshoot
Post-transition undershoot
Upper (s )
s
Lower (s )
Pre-transition
Post-transition
aberration region
aberration region
Upper (s )
s
Pre-transition undershoot
Lower (s )
Pre-transition overshoot
Waveform epoch
t IEC  856/13
Figure 5 – Overshoot and undershoot in single positive-going transition

Pre-transition overshoot
Pre-transition undershoot
Upper (s )
s
Lower (s )
Pre-transition Post-transition
aberration region aberration region
Upper (s )
s
lower (s )
Post-transition overshoot
Post-transition undershoot
Waveform epoch
t
0 IEC  857/13
Figure 6 – Overshoot and undershoot in a single negative-going transition

– 16 – 60469 © IEC:2013
3.2.20
parameter
any value (number multiplied by a unit of measure) that can be calculated from a waveform
3.2.20.1
level parameter
parameter whose units are the same as the units of levels
3.2.20.2
time parameter
parameter whose units are a unit of time
3.2.21
maximum peak
pertaining to the greatest value of the waveform
3.2.22
minimum peak
pertaining to the least value of the waveform
3.2.23
peak-to-peak
pertaining to the value of the difference between the extrema of the specified waveform
3.2.24
periodic
identically recurring at equal intervals of the independent variable (IEV)
Note 1 to entry: The independent variable is often time.
[IEC 60050-103:2009,103-05-09, modified – the note to entry has been replaced.]
3.2.25
aperiodic
not recurring at equal intervals of the independent variable
Note 1 to entry: The independent variable is often time.
3.2.26
precision
closeness of agreement between indications or measured quantity values obtained by
replicate measurements on the same or similar objects under specified conditions
[ISO/IEC Guide 99:2007, 2.15, modified – the notes in the original definition have been
deleted.]
3.2.27
pulse duration
DEPRECATED: pulse width
difference between the first and second transition occurrence instants
SEE Figure 3 and Figure 4.
Note 1 to entry Pulse width, as well as full width at half maximum (FWHM) and half width at half maximum (HWHM)
are, in general, deprecated terms, because width is a word that denotes a spatial parameter whereas the
parameter of interest is time. However, in some applications it may be desireable to discuss the spatial location of
a propagating pulse and its spatial distribution, i.e., pulse width in matter or space. FWHM, HWHM, and full
duration at half maximum (FDHM) are deprecated terms because of the reference to the maximum value of the
waveform, where the waveform amplitude may be either positive or negative and the waveform may contain noise.

60469 © IEC:2013 – 17 –
3.2.28
pulse separation
duration between the 50 % reference level instant, unless otherwise specified, of the second
transition of one pulse in a pulse train and that of the first transition of the immediately
following pulse in the same pulse train
3.2.29
pulse train
repetitive sequence of pulse waveforms. Unless otherwise specified, all of the pulse
waveforms in the sequence are assumed to be identical
SEE: Figure 7 and Figure A.12.

s
Pulse period
Pulse separation
50 % reference level
Pulse duration
s
Base state
Waveform epoch
t
IEC  858/13
Figure 7 – Pulse train
3.2.30
pulse waveform
DEPRECATED: leading edge
DEPRECATED: trailing edge
waveform whose level departs from one state, attains another state, and ultimately returns to
the original state
SEE: Figures 3 and Figure 4.
Note 1 to entry: As defined here, a pulse waveform consists of two transitions and two states. (See Clause 4.)
Alternatively, a pulse waveform can be described as a compound waveform consisting of the sum of a positive
(negative) step-like waveform and a delayed negative (positive) step-like waveform both having the same unsigned
waveform amplitude.
Note 2 to entry: Leading edge and trailing edge are deprecated because 1) the word edge describes the property
of a geometric figure, which is not contained by or representative of the physical signal that corresponds to the
waveform and 2) the terms first and second adequately and unambiguously describe the meanings of leading and
trailing.
– 18 – 60469 © IEC:2013
3.2.30.1
negative pulse waveform
pulse waveform whose first transition is a negative-going transition
SEE: Figure 4.
3.2.30.2
positive pulse waveform
pulse waveform whose first transition is a positive-going transition
SEE: Figure 3.
3.2.31
reference
of or pertaining to a time, level, waveform feat
...