Zero-crossing direction and time interval jitter measurement apparatus using offset sampling
US6865496B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 2001 |
| Grant date | Mar 8, 2005 |
| Priority date | — |
| Expiry date | Mar 7, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/205
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A sampling apparatus for use in high data rate jitter measurement systems based on offset sampling uses a trigger circuit, along with a time-based variable delay, to align a sampling strobe to drive two samplers. An input data signal is split and fed via separate signal paths into the two samplers. One of the samplers is delayed in sampling the input signal or the input is delayed to one of the samplers, such that the two samples of the input signal are offset in time. The jitter present in the SUT can be calculated using the two samples. In addition, when using two strobe circuits, the jitter inherently present in the strobe circuits can be compensated for by offset sampling a reference clock with each main strobe to determine the phase and cycle number of the reference clock at each strobe time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.