ZHCSJI7 March   2019 SN74AXCH4T245

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     功能方框图
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
    1.     Pin 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, VCCA = 0.7 ± 0.05 V
    7. 6.7  Switching Characteristics, VCCA = 0.8 ± 0.04 V
    8. 6.8  Switching Characteristics, VCCA = 0.9 ± 0.045 V
    9. 6.9  Switching Characteristics, VCCA = 1.2 ± 0.1 V
    10. 6.10 Switching Characteristics, VCCA = 1.5 ± 0.1 V
    11. 6.11 Switching Characteristics, VCCA = 1.8 ± 0.15 V
    12. 6.12 Switching Characteristics, VCCA = 2.5 ± 0.2 V
    13. 6.13 Switching Characteristics, VCCA = 3.3 ± 0.3 V
    14. 6.14 Operating Characteristics: TA = 25°C
    15. 6.15 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Load Circuit and Voltage Waveforms
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Standard CMOS Inputs
      2. 8.3.2  Balanced High-Drive CMOS Push-Pull Outputs
      3. 8.3.3  Partial Power Down (Ioff)
      4. 8.3.4  VCC Isolation
      5. 8.3.5  Over-voltage Tolerant Inputs
      6. 8.3.6  Glitch-free Power Supply Sequencing
      7. 8.3.7  Negative Clamping Diodes
      8. 8.3.8  Fully Configurable Dual-Rail Design
      9. 8.3.9  Supports High-Speed Translation
      10. 8.3.10 Bus-Hold Data Inputs
    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
      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. 12器件和文档支持
    1. 12.1 相关文档　
    2. 12.2 接收文档更新通知
    3. 12.3 社区资源
    4. 12.4 商标
    5. 12.5 静电放电警告
    6. 12.6 术语表
  13. 13机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

8.3.10 Bus-Hold Data Inputs

Each data input on this device includes a weak latch that maintains a valid logic level on the input. The state of these latches is unknown at startup and remains unknown until the input has been forced to a valid high or low state. After data has been sent through a channel, the latch then maintains the previous state on the input if the line is left floating. It is not recommended to use pull-up or pull-down resistors together with a bus-hold input, as it may cause undefined inputs to occur which leads to excessive current consumption.

Bus-hold data inputs prevent floating inputs on this device. The Implications of Slow or Floating CMOS Inputs application report explains the problems associated with leaving CMOS inputs floating.

These latches remain active at all times, independent of all control signals such as direction control or output enable.

The Bus-Hold Circuit application report has additional details regarding bus-hold inputs.

SN74AXCH4T245 Feature_Bus-Hold.gifFigure 10. Simplified Schematic For Device With Bus-Hold Data Inputs