Apparatus and method for decoding differential multi-level data with adaptive threshold control
US5969646A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1998 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Mar 25, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/061
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An improved decoder for recovering Non-Return-to-Zero Interface (NRZI) digital data from a multiple layer transition (MLT-3) encoded signal in a 100BASE-TX Ethernet (IEEE Standard 802.3u) uses multiple comparators to minimize jitter in the decoded signal. A CMOS-based biasing circuit receives the differential MLT-3 encoded input signals and control signals from a signal amplitude detection circuit. The biasing circuit adjusts for any DC offset, and also generates offset signals based on respective mid-peak voltage values of the respective differential input signals. Four comparators are then used to detect a prescribed edge transition (e.g., a positive edge) coinciding with the respective mid-peak voltage value in the respective signals. The detected edge transitions are then used by edge decoding logic to generate the NRZI bilevel signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.