JAJSUL9C September   2003  – May 2024 SN74LVC257A-Q1

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 概要
  4. 3 Pin Configuration and Functions
  5. 4 Specifications
    1. 4.1 Absolute Maximum Ratings
    2. 4.2 ESD Ratings
    3. 4.3 Recommended Operating Conditions
    4. 4.4 Thermal Information
    5. 4.5 Electrical Characteristics
    6. 4.6 Switching Characteristics
    7. 4.7 Operating Characteristics
  6. 5 Parameter Measurement Information
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Power Supply Recommendations
    2. 7.2 Layout
      1. 7.2.1 Layout Guidelines
      2. 7.2.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support (Analog)
      1. 8.1.1 Related Links
    2. 8.2 ドキュメントの更新通知を受け取る方法
    3. 8.3 サポート・リソース
    4. 8.4 Trademarks
    5. 8.5 静電気放電に関する注意事項
    6. 8.6 用語集
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

パッケージ・オプション

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ（パッケージ｜ピン）
  • BQB|16
  • PW|16
  • D|16
サーマルパッド・メカニカル・データ
発注情報

7.2.1 Layout Guidelines

When using multiple bit logic devices, inputs must not float. In many cases, functions or parts of functions of digital logic devices are unused. Some examples are when only two inputs of a triple-input AND gate are used, or when only 3 of the 4-buffer gates are used. Such input pins must not be left unconnected because the undefined voltages at the outside connections result in undefined operational states.

Specified in Layout Example for the SN74LVC257A-Q1 are rules that must be observed under all circumstances. All unused inputs of digital logic devices must be connected to a high or low bias to prevent them from floating. The logic level that must be applied to any particular unused input depends on the function of the device. Generally they will be tied to GND or VCC, whichever makes more sense or is more convenient.