ZHCSOE9 April   2022 SN74LXCH1T45

PRODUCTION DATA  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  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, VCCA = 1.2 ± 0.1 V
    7. 6.7  Switching Characteristics, VCCA = 1.5 ± 0.1 V
    8. 6.8  Switching Characteristics, VCCA = 1.8 ± 0.15 V
    9. 6.9  Switching Characteristics, VCCA = 2.5 ± 0.2 V
    10. 6.10 Switching Characteristics, VCCA = 3.3 ± 0.3 V
    11. 6.11 Switching Characteristics, VCCA = 5.0 ± 0.5 V
    12. 6.12 Switching Characteristics: Tsk, TMAX
    13. 6.13 Operating Characteristics
    14. 6.14 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  CMOS Schmitt-Trigger Inputs
        1. 8.3.1.1 Control Inputs with Integrated Static Pull-Down Resistors
      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 and VCC Disconnect
      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 Enable Times
    3. 9.3 Typical Application
      1. 9.3.1 Design Requirements
      2. 9.3.2 Detailed Design Procedure
      3. 9.3.3 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 接收文档更新通知
    3. 12.3 支持资源
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 术语表
  13. 13Mechanical, Packaging, and Orderable Information

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 is sent through a channel, the latch 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 the CMOS inputs floating. These latches remain active at all times, independent of all control signals such as direction control or output enable. The latches also remain active when the device is in the partial power down state, corresponding supply is still present, or when the I/O's are floated. The Bus-Hold Circuit application report has additional details regarding bus-hold inputs.

GUID-60BFB3F2-42F4-4A9D-9B65-DD3D96B22A64-low.gif Figure 8-3 Schematic Description of Location of Bus-Hold Circuits