Open collector communications link
US5587824A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 1, 1995 |
| Grant date | Dec 24, 1996 |
| Priority date | — |
| Expiry date | Sep 1, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/023
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A bidirectional, long-distance open collector link is constructed between a pair of spaced-apart open collector ports, with each of the ports being coupled to one input of a comparator. The other input of the comparator is responsive to a reference voltage and the comparator of the opposite port via an extended conductor. A first diode poled to pass current from the respective port is coupled between inputs of each comparator, and a second diode is coupled in the extended conductor to pass current to the opposite port. As such, when a first port goes LOW, a first comparator operatively associated with that port provides a LOW to the input of the second comparator, causing it to provide a HIGH output and also pulls the second port LOW. The HIGH from the second comparator is used to clamp the first comparator LOW as long as the port asserts a LOW.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.