General Description

The 74ACT1284 contains four non-inverting bidirectional buffers and three non-inverting buffers with open Drain outputs and high drive capability on the B Ports. It is intended to provide a standard signaling method for a bi-direction parallel peripheral in an Extended Capabilities Port mode (ECP).

The HD (active HIGH) input pin enables the B Ports to switch from open Drain to a high drive totem pole output, capable of sourcing 14 mA on all seven buffers. The DIR input determines the direction of data flow on the bidirectional buffers. DIR (active HIGH) enables data flow from A Ports to B Ports. DIR (active LOW) enables data flow from B Ports to A Ports.

Features

■ TTL-compatible inputs

■ A Ports have standard 4 mA totem pole outputs

■ Typical input hysteresis of 0.5V

■ B Port high drive source/sink capability of 14 mA

■ Bidirectional non-inverting buffers

■ Supports IEEE P1284 Level 1 and Level 2 signaling

standards for bidirectional parallel communications

between personal computers and printing peripherals

■ B Port outputs in High Impedance mode during power down

■ Guaranteed 4000V minimum ESD protection