SCLS918 april   2023 SN74LV4T00

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  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 1.8-V VCC
    7. 6.7  Switching Characteristics 2.5-V VCC
    8. 6.8  Switching Characteristics 3.3-V VCC
    9. 6.9  Switching Characteristics 5.0-V VCC
    10. 6.10 Noise Characteristics
  7. 7 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Balanced CMOS 3-State Outputs
      2. 9.3.2 Clamp Diode Structure
      3. 9.3.3 LVxT Enhanced Input Voltage
        1. 9.3.3.1 Down Translation
        2. 9.3.3.2 Up Translation
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
        1. 10.2.1.1 Power Considerations
        2. 10.2.1.2 Input Considerations
        3. 10.2.1.3 Output Considerations
      2. 10.2.2 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

10.1 Application Information

In this application, two 2-input NAND gates are used to create an active-low SR latch as shown in Figure 10-1. The two additional gates can be used for a second SR latch, or the inputs can be grounded and both channels left unused.

The SN74LV4T00 is used to drive the tamper indicator LED and provide one bit of data to the system controller. When the tamper switch outputs LOW, the output Q becomes HIGH. This output remains HIGH until the system controller addresses the event and sends a LOW signal to the R input which returns the Q output back to LOW.

The inputs of this active-low SR latch can often be driven by open-drain outputs which can produce slow input transition rates when they transition from LOW to Hi-Z. This makes the SN74LV4T00 ideal for the application because it has Schmitt-trigger inputs that do not have input transition rate requirements.