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7-Bit Bus Interfaces With 3-State Outputs


Package | PIN: DB | 20
Temp: C (0 to 70)
Carrier: Cut Tape
Qty Price
1-9 $1.16
10-24 $1.04
25-99 $0.96
100-249 $0.82
250-499 $0.76
500-749 $0.62
750-999 $0.49
1000+ $0.44


  • 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

Texas Instruments  SN74ACT1284DBR

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.