High speed logic apparatus
US4647800A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1985 |
| Grant date | Mar 3, 1987 |
| Priority date | — |
| Expiry date | Dec 9, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/04166
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A high speed laser driver includes a differential pair of bipolar transistors sharing a common emitter resistor as in the prior art. However, an improvement thereover resides in the use of Schottky barrier diodes, one of which couples the emitter of one transistor to the common emitter resistor and the other of which couples the emitter of the other transistor to the common emitter resistor. Furthermore, separate resistors couple the emitters of both transistors to a voltage source so that the transistors are always conducting. A high speed logic circuit includes a pair of input bipolar transistors, and a reference transistor, sharing a common emitter resistor as in the prior art. However, an important resides thereover in the use of Schottky barrier diodes that couple the emitters of the transistors to the common emitter resistor. Furthermore, separate resistors couple the emitters of the three transistors to a voltage source so that the transistors are always conducting. Schottky barrier diodes are used in the emitters of ECL logic circuits, substantially increasing switching speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.