JAJSNK1A August   2020  – December 2021 SN74HCS157-Q1

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     4
    2.     5
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Operating Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Balanced CMOS Push-Pull Outputs
      2. 8.3.2 CMOS Schmitt-Trigger Inputs
      3. 8.3.3 Clamp Diode Structure
      4. 8.3.4 Wettable Flanks
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Power Considerations
        2. 9.2.1.2 Input Considerations
        3. 9.2.1.3 Output Considerations
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.2.2 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 ≤ 50 pF. This is not a hard limit, however it will ensure optimal performance. This can be accomplished by providing short, appropriately sized traces from the SN74HCS157-Q1 to the receiving device(s).
  3. Ensure the resistive load at the output is larger than (VCC / IO(max)) Ω. This will ensure that the maximum output current from the Absolute Maximum Ratings is not violated. Most CMOS inputs have a resistive load measured in megaohms; much larger than the minimum calculated above.
  4. Thermal issues are rarely a concern for logic gates, however the power consumption and thermal increase can be calculated using the steps provided in the application report, CMOS Power Consumption and Cpd Calculation.