SN74ACT1284DBR.A中文资料德州仪器数据手册PDF规格书

4.5-V to 5.5-V VCC Operation

Inputs Accept Voltages to 5.5 V

Max tpd of 20 ns at 5 V

3-State Outputs Directly Drive Bus Lines

Flow-Through Architecture Optimizes PCB

Layout

Center-Pin VCC and GND Configurations

Minimize High-Speed Switching Noise

ESD Protection Exceeds JESD 22

− 2000-V Human-Body Model (A114-A)

− 200-V Machine Model (A115-A)

Designed for the IEEE 1284-I (Level-1 Type)

and IEEE 1284-II (Level-2 Type) Electrical

Specifications

description/ordering information

The ’ACT1284 devices are designed for

asynchronous two-way communication between

data buses. The control function minimizes

external timing requirements.

The devices allow data transmission in either the

A-to-B or the B-to-A direction for bits 1, 2, 3, and

4, depending on the logic level at the

direction-control (DIR) input. Bits 5, 6, and 7,

however, always transmit in the A-to-B direction.

The output drive for each mode is determined by the high-drive (HD) control pin. When HD is high, the high drive

is delivered by the totem-pole configuration, and when HD is low, the outputs are open drain. This meets the

drive requirements as specified in the IEEE 1284-I (level-1 type) and the IEEE 1284-II (level-2 type) parallel

peripheral-interface specification.