Low power high current sinking TTL circuit
US4697103A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1986 |
| Grant date | Sep 29, 1987 |
| Priority date | — |
| Expiry date | Mar 10, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/0136
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A multi-terminal transistor circuit structure is described for TTL applications including current sinking and "pull-down" transistor circuit elements. A transistor pair is coupled with the emitter of the second transistor coupled to the base of the first transistor. The collector and emitter of the first transistor provide first and second terminals and the bases of the transistor pair provide independent third and fourth terminals or current controlled inputs. The new circuit structure is incorporated in a tranistor transistor logic (TTL) output buffer circuit and provides first and second pull-down transistor elements having the emitter of the second transistor coupled to the base of the first pull-down transistor. An independent base drive is coupled to the base of the second pull-down transistor element. The second stage pull-down transistor element introduces full square law enhancement of .beta..sup.2 amplification of the output sinking current in a high current sinking mode while eliminating prior art feedback diodes and dual phase splitter transistors. The separate input and base drive coupling to the base of the additional pull-down avoids "current hogging" of the base dri…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.