Clock distribution apparatus with current sensed skew cancelling
US5852640A · kind A · utility
Inventors
Key dates
| Filing date | Jun 26, 1995 |
| Grant date | Dec 22, 1998 |
| Priority date | — |
| Expiry date | Jun 26, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A clock distribution apparatus with active phase alignment which makes the incidence of a timing event occur essentially simultaneously at multiple physically remote destinations. The circuit uses traces configured as reflective transmission lines with a matched impedance input. The propagation time of a transmission line is determined by monitoring the current into the transmission line. Variable delays are determined for each transmission line by measuring the actual propagation time and reducing a predetermined maximum delay time by that amount. The variable delay values are stored and used to retard clock edges by the varying amounts so that all clock edges arrive at respective remote destinations at a time equal to the maximum delay time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.