SCLS255N December   1995  – February 2024 SN54AHC74 , SN74AHC74

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information — SN74AHC74
    5. 5.5  Electrical Characteristics
    6. 5.6  Timing Requirements — VCC = 3.3 V ± 0.3 V
    7. 5.7  Timing Requirements — VCC = 5 V ± 0.5 V
    8. 5.8  Switching Characteristics — VCC = 3.3 V ± 0.5 V
    9. 5.9  Switching Characteristics — VCC = 5 V ± 0.5 V
    10. 5.10 Noise Characteristics
    11. 5.11 Operating Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Input Considerations
        2. 8.2.1.2 Output Considerations
        3. 8.2.1.3 Power Considerations
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • J|14
  • FK|20
  • W|14
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.1.1 Input Considerations

Input signals must cross VIL(max) to be considered a logic LOW, and VIH(min) to be considered a logic HIGH. Do not exceed the maximum input voltage range found in the Absolute Maximum Ratings.

Unused inputs must be terminated to either VCC or ground. The unused inputs can be directly terminated if the input is completely unused, or they can be connected with a pull-up or pull-down resistor if the input will be used sometimes, but not always. A pull-up resistor is used for a default state of HIGH, and a pull-down resistor is used for a default state of LOW. The drive current of the controller, leakage current into the SNx4AHC74 (as specified in the Electrical Characteristics), and the desired input transition rate limits the resistor size. A 10-kΩ resistor value is often used due to these factors.

The SNx4AHC74 has CMOS inputs and thus requires fast input transitions to operate correctly, as defined in the Recommended Operating Conditions table. Slow input transitions can cause oscillations, additional power consumption, and reduction in device reliability.

Refer to the Feature Description section for additional information regarding the inputs for this device.