Tri-state cmos driver having reduced gate delay

Abstract

A Tri-State circuit element is constructed which is uniquely suited for use in large scale integrated circuit devices wherein a relatively large number of such Tri-State circuits are utilized to drive other circuitry contained within the integrated circuit device. One embodiment of a Tri-State circuit is constructed utilizing a single NAND gate (73), a single inverter (74), a single P channel transistor (76), and two N channel transistors (77, 78) yielding a circuit having a propagation delay of only two gate delays and requiring a total of only nine transistors. Another embodiment of this invention is a Tri-State circuit constructed utilizing a single NOR gate (84), a single inverter (83), a single N channel transistor (88), and two P channel transistors (86, 87). In this embodiment of my invention, a total of nine MOS transistors are required, and the propagation delay between the input terminal and the output terminal is equal to two gate delays.