Serial digital data communications receiver with improved automatic cable equalizer, AGC system, and DC restorer
US6501792B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 6, 2001 |
| Grant date | Dec 31, 2002 |
| Priority date | — |
| Expiry date | Sep 6, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/063
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A serial digital data communications receiver with an improved automatic cable equalizer that is less susceptible to jitter and has greater multi-standards capability, and an improved automatic gain control system with a DC restorer that provides optimal edge jitter performance while avoiding the possibility of a latch-up condition at the start of data transmission. The automatic cable equalizer for equalizing signals received over cables of different lengths has multiple stages each having a transfer function of 1+Ki[fi(j&ohgr;)] wherein each of the Ki vary in accordance with a sequential gain control methodology. The AGC system uses the difference between band-pass filtered versions of the amplitudes of the input and output of a DC restorer based on quantized feedback, to regulate the AGC circuit. The DC restorer comprises a comparator for generating a quantized output and further clamps the input with a clamping circuit so that a version of the quantized output is fed back to the input while avoiding the possibility of operational failure of the comparator at the onset of data transmission.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.