SCLS885 December   2022

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 (1)
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics
    6. 6.6  Switching Characteristics - VCC = 2.5 V ± 0.25 V
    7. 6.7  Switching Characteristics - VCC = 3.3 V ± 0.3 V
    8. 6.8  Switching Characteristics - VCC = 5 V ± 0.5 V
    9. 6.9  Operating Characteristics
    10. 6.10 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 Standard CMOS Inputs
      2. 8.3.2 Balanced CMOS Push-Pull Outputs
      3. 8.3.3 Partial Power Down (Ioff)
      4. 8.3.4 Wettable Flanks
      5. 8.3.5 Clamp Diode Structure
    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 Power Considerations
      2. 9.2.2 Input Considerations
      3. 9.2.3 Output Considerations
      4. 9.2.4 Detailed Design Procedure
      5. 9.2.5 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.4 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; it will, however, ensure optimal performance. This can be accomplished by providing short, appropriately sized traces from the SN74LV138A-Q1 to one or more of the receiving devices.
  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 MΩ; much larger than the minimum calculated previously.
  4. Thermal issues are rarely a concern for logic gates; the power consumption and thermal increase, however, can be calculated using the steps provided in the application report, CMOS Power Consumption and Cpd Calculation.