Jitter is typically measured in Unit Intervals (UI) or picoseconds (ps). One UI is the time period of a single bit. Jitter: Jitter is the short-term phase variations of the significant instants of a digital signal from their ideal positions in time. Imagine a perfectly metronomic drummer suddenly speeding. This introduction to jitter presents definitions for various jitter types including the random jitter types: Gaussian, cycle-to-cycle, adjacent cycle; and deterministic jitter types: duty cycle distortion, pulse width distortion, pulse skew and data dependent (pattern) jitter. The application note. The Telecommunications Networks Test Division of Agilent Technologies (formerly Hewlett-Packard) in Scotland introduced the first jitter measurement instrument in 1982 for PDH rates up to E3 and DS3, followed by one of the first 140 Mb/s jitter testers in 1984., that affect communications quality over Fibre Channel, Infiniband, 10GbE, USB, PCI, etc.
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