Differential bus with specified default value
US5056110A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1989 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Dec 11, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0298
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A solution to the problem in differential buses that the bus state for a given line pair is undefined when no unit is driving either of the bus lines in the pair. The lines in the bus pair are terminated to different voltage levels, thereby establishing a desired default condition when no unit is driving either line. The voltage offset between the two bus lines must be sufficient that differential receivers coupled to the bus when the bus is not driven can respond to the offset. At the same time, the offset must not be so great that a driver attempting to drive the bus pair cannot overcome the offset with enough margin for the receivers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.