General Description

This family of Advance Schottky 3-STATE Bus circuits are designed to provide either bidirectional or unidirectional buffer interface in Memory, Microprocessor, and Communication Systems. The output characteristics of the circuits have low impedance sufficient to drive terminated transmission lines down to 133Ω. The input characteristics of the circuits likewise have a high impedance so it will not significantly load the transmission line. The package contains eight 3-STATE buffers organized with four buffers having a common 3-STATE enable gate. The DM74AS240 and DM74AS244 are eight wide in a 20 pin package, and may be used as a 4 wide bidirectional or eight wide unidirectional. The buffer selection includes inverting and noninverting, with enable or disable 3-STATE control.

Features

■ Advanced oxide-isolated, ion-implanted Schottky TTL process

■ Improved switching performance with less power dissipation compared

with Schottky counterpart

■ Functional and pin compatible with 74LS and Schottky counterpart

■ Switching response specified into 500Ω and 50 pF

■ Specified to interface with CMOS at VOH = VCC − 2V