The CDx4HC243 and CDx4HCT243 silicon-gate CMOS three-state bidirectional noninverting buffers are intended for two-way asynchronous communication between data buses. They have high-drive-current outputs that enable high-speed operation when driving large bus capacitances. These circuits possess the low power dissipation of CMOS circuits and have speeds comparable to low-power Schottky TTL circuits. They can drive 15 LSTTL loads.

The states of the output-enable (OEB, OEA) inputs determine both the direction of flow (A to B, B to A), and the three-state mode.