Instrumentation & Measurement Magazine 23-8 - 11

The 1658 Subcommittee is currently involved in the revision of the Standard, after 10 years from the first publication.

IEEE Std 1696-2013: "Standard for Terminology
and Test Methods for Circuit Probes" [5] and the
Subcommittee on Probe Standards (SCOPS)
(Std 1696)
The IEEE Std 1696 describes test methods and transfer (artifact) standards for characterizing electrical circuit probes and
probes systems. The systems may include waveform acquisition hardware and software and signal/waveform analysis
software. The probe will include the mechanism by which the
circuit is contacted. This method and standard will be applicable to all individual probes having one signal conductor and
one ground conductor, or two signal conductors, and having
input impedance greater than the impedance of the circuit under test.
The IEEE Std 1696-2013 describes methods to measure 20
different performance parameters of a circuit probe, such as
input resistance, output resistance, gain, frequency response,
step response, and many others. These measurements are
based on the use of a probe-characterization test fixture (artifact standard). Furthermore, the standard describes test
methods to perform these measurements for single-ended
or differential probes as well as probe-only and probe-system techniques. Fig. 3 shows an example from the standard of
the test setup for measuring the input impedance of a singleended stand-alone probe.
The ability to accurately characterize circuit probes enables
probe users to fully understand a circuit probe's effect on their
circuits. Circuit probe characterization can support the systematic removal of the probe effects from the measured data,
resulting in a more accurate and complete representation of a
measurement system's electrical performance than if the probe
effects were not removed.

Fig. 4. Example fixture (differential fixture shown) and block diagram for
probe measurement.

Circuit probe characterization starts with a carefully designed and accurately characterized probe-characterization
test fixture. Fig. 4 shows an example of a probe-characterization test fixture and its electrical block diagram.
Once an accurate probe-characterization test fixture is obtained, the probe plus the test fixture must be accurately
measured to get their joint electrical characteristics. The block
diagram shows the S21-through-measurement approach. These
joint electrical response characteristics can subsequently be converted to a probe-only response using data available on the
probe-characterization test fixture. Once the probe's frequencyresponse characteristics are known, the probe's effects on the
circuit can then be accurately quantified and/or removed from
subsequent electrical measurements of the response of a measurement instrument, such as a waveform recorder.

IEEE Draft Std P2414: "Draft Standard for Jitter
and Phase Noise" and the Subcommittee on
Jitter (P2414)

Fig. 3. Test setup for measuring the input impedance of single-ended standalone probe.
November 2020

The IEEE Std 2414 is being written to define specifications,
models and terminology that describe the dispersion of specified instants of repetitive and/or periodic signals in electronics,
telecommunications and measurement, which are referred to
as jitter and phase noise. Jitter occurs in many different parts of
digital systems such as the jitter of data with respect to clock in

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