Diode controlled idle current injection
US3955099A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1974 |
| Grant date | May 4, 1976 |
| Priority date | — |
| Expiry date | Mar 11, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/013
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Diodes having a fast response time are used in an Emitter-Coupled Logic (ECL) current switch circuit to cause the injection of an idle current in each of the transistors of said switch. The injection of the idle current through these transistors causes them to operate at all times in an active region. When the transistors remain in the active operating region and are subjected to a switching transient, the parasitic capacitance associated with emitter base and collector base junctions are not charged and discharged to the same extent that they would be if the transistor was turned off completely. Moreover, if the transistors are held on, delay required for minority profile "buildup" in the base region is reduced and the current switch's propagation delay is reduced. When the fast response diodes are used to cause the injection of idle current in a cascode circuit, the overall transient response is greatly improved in both the lower and upper current switch sections; and there is a reduction of spurious output signals. Schottky diodes can be used in said circuit due to their fast response time. Alternatively large value resistors or current source transistors are used when diodes ar…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.