SCASE14 September   2024 SN74AC3G98

ADVANCE INFORMATION  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Pin Configuration and Functions
  6. Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Electrical Characteristics
    4. 5.4 Recommended Operating Conditions
    5. 5.5 Thermal Information
    6. 5.6 Switching Characteristics
  7. Parameter Measurement Information
  8. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Balanced CMOS Push-Pull Outputs
      2. 7.3.2 CMOS Schmitt-Trigger Inputs
      3. 7.3.3 Clamp Diode Structure
    4. 7.4 Device Functional Modes
    5. 7.5 Combinatorial Logic Configurations
  9. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Power Considerations
        2. 8.2.1.2 Input Considerations
        3. 8.2.1.3 Output Considerations
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
      4. 8.2.4 Power Supply Recommendations
      5. 8.2.5 Layout
        1. 8.2.5.1 Layout Guidelines
        2. 8.2.5.2 Layout Example
  10. 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
    1. 11.1 Tape and Reel Information
    2. 11.2 Mechanical Data

Package Options

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

Detailed Design Procedure

  1. Add a decoupling capacitor from VCC to GND. The capacitor needs to be placed physically close to the device and electrically close to both the VCC and GND pins. An example layout is shown in the Layout section.
  2. Ensure the capacitive load at the output is ≤ 50pF. This is not a hard limit; by design, however, it will optimize performance. This can be accomplished by providing short, appropriately sized traces from the SN74AC3G98 to one or more of the receiving devices.
  3. Ensure the resistive load at the output is larger than (VCC / IO(max))Ω. Doing this will prevent the maximum output current from the Absolute Maximum Ratings from being violated. Most CMOS inputs have a resistive load measured in MΩ; much larger than the minimum calculated previously.
  4. Thermal issues are rarely a concern for logic gates; the power consumption and thermal increase, however, can be calculated using the steps provided in the application report, CMOS Power Consumption and Cpd Calculation.