Circuit and method for twisted pair current source driver
US5485488A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1994 |
| Grant date | Jan 16, 1996 |
| Priority date | — |
| Expiry date | Mar 29, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0276
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A mechanism and method for efficiently communicating information regarding particular communication rate ("speed signal") between two or more communication stations (of a communication network). The transmitter operates on the IEEE P1394 High Performance Serial Bus to supply both differential and common mode signaling required by the IEEE standard for exemplary data transfer rates of 100 and 200 Mbit transmission. The present invention includes a transmission circuit that may operate in a differential signal mode and simultaneously in a common mode signal mode both utilizing a twisted pair cable. Data may be transmitted on the twisted pair at small differential signals. Information regarding the signal speed between two coupled units may be simultaneously transmitted using variations in the common mode voltage over the twisted pair. Communication may be initiated at a slower communication rate and then upgraded as appropriate for the two units. The present invention allows an efficient single circuit mechanism for communication units to transmit differential data and also to signal the use of a high speed communication rate with a common mode voltage. The present invention is espec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.