An extended logic family of cascode current switch (CSC) logic circuits.

摘要

The present logic circuit family is derived from the conventional 2 level single-ended cascode logic circuit. The basic logic circuit performing a 2-2 OA/OAI 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; said 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.