SCAS971 March   2024 SN74ACT245-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Switching Characteristics
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Balanced CMOS 3-State Outputs
      2. 7.3.2 TTL-Compatible CMOS Inputs
      3. 7.3.3 Wettable Flanks
      4. 7.3.4 Clamp Diode Structure
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
    3. 8.3 Design Requirements
      1. 8.3.1 Power Considerations
      2. 8.3.2 Input Considerations
      3. 8.3.3 Output Considerations
    4. 8.4 Detailed Design Procedure
    5. 8.5 Application Curves
    6. 8.6 Power Supply Recommendations
    7. 8.7 Layout
      1. 8.7.1 Layout Guidelines
      2. 8.7.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.1 Overview

The SN74ACT245-Q1 is an octal bus transceiver with 3-state outputs. All eight channels are controlled by the direction (DIR) pin and output enable (OE) pin. Each transceiver includes one buffer oriented from Ax to Bx and one from Bx to Ax, with at least one output disabled at all times. The direction (DIR) pin controls which buffer is active. The buffer that is not active has the output placed into the high-impedance state.

The output enable (OE) controls all outputs in the device. When the OE pin is in the low state, the appropriate outputs as determined by the direction (DIR) pin are enabled. When the OE pin is in the high state, all outputs of the device are disabled. All disabled outputs are placed into the high-impedance state.

To put the device in the high-impedance state during power up or power down, tie OE pin to VCC through a pull-up resistor and drive the OE pin low once the system is ready to begin normal operation. The current sinking capability of the driver and the leakage of the pin determines the minimum value of the resistor (as defined in the Electrical Characteristics table). Typically a 10kΩ resistor will be sufficient.