Flexible timebase for eye diagram
US8355469B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 2011 |
| Grant date | Jan 15, 2013 |
| Priority date | — |
| Expiry date | Jul 8, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/31727
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A flexible timebase for eye diagrams uses a stable free running oscillator as a sample clock for equivalent time sampling of an input serial digital signal and of a reference signal, derived from a subdivided recovered clock of the input serial digital signal. The reference signal samples are provided to a digital phase-locked loop that provides the flexible timebase to an eye pattern generator. The eye pattern generator accumulates the input serial digital signal samples at times corresponding to the reference signal samples to produce the eye diagram. A linear phase detector in the digital phase locked loop converts the reference signal samples to a complex signal using a Hilbert transform and then to a linear ramp of phase values using a CORDIC algorithm with arctangent lookup table. A subtractor then subtracts the digital phase-locked loop feedback from the linear ramp to provide the input to the loop filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.