Instrumentenjitter

Instrumentenjitter is a term used to describe the timing variability observed in measurement equipment and instruments that affects the timing of sampled signals or events. It is distinct from the jitter of the signal under test; rather it characterizes the randomness or systematic drift introduced by the instrument itself. The term is not universally standardized and is sometimes used interchangeably with jitter of the signal under test.

Common sources include clock jitter from the instrument's reference oscillator, sampling clock skew, digital processing delays, temperature- and power-supply induced drift, and imperfect synchronization between subsystems.

In practice instrumentenjitter manifests as small deviations in edge timing, phase, or pulse width, which can degrade measurement accuracy, especially in high-speed or high-resolution tests. It is relevant for oscilloscopes, spectrum analyzers, time-interval analyzers, and data acquisition systems.

Measurement and characterization: use of time-interval error (TIE), time deviation (TDEV), and jitter RMS; analysis of histograms of edge timestamps; spectrum of phase noise; use of references, cross-checks with external standards.

Mitigation: choosing low-jitter reference clocks, proper clock distribution, temperature regulation, robust grounding, calibration, using differential signaling, shielding, and selecting ADCs with specified jitter budgets; design practices: synchronous architectures, PLLs with specified jitter budgets.