Cascode logic circuit including a positive level shift at the input of the top logic stage
US4942316A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1988 |
| Grant date | Jul 17, 1990 |
| Priority date | — |
| Expiry date | Nov 25, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/1738
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A logic circuit family derived from the conventional 2 level single-ended cascode logic circuit. The basic logic circuit performing a 2--2 OA/AI logic function shown in the attached drawing is given for illustration purposes. It comprises: a logic tree 35 comprised of top and bottom stages 37, 36 dotted at the tree output 38 to perform a determined logic function; the top stage 37 includes a current switch comprised of two input transistors TX34, TX35 connected in a differential amplifier configuration with a reference transistor TX36. The bases of input transistors TX34, TX35 are provided with at least two level shifter devices. Preferably, input level shifter devices are Schottky diodes P31, . . . which move the voltages towards the more positive voltage VPP, to add an AND function on each of these input transistors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.