SCHS289A December   1998  – May 2024 CD54AC373 , CD54ACT373 , CD74AC373 , CD74ACT373

PRODMIX  

  1.   1
  2. Features
  3. Description
  4. Pin Configuration and Functions
  5. Specifications
    1. 4.1  Absolute Maximum Ratings
    2. 4.2  ESD Ratings
    3. 4.3  Recommended Operating Conditions
    4. 4.4  Thermal Information
    5. 4.5  Electrical Characteristics: AC Series
    6. 4.6  Electrical Characteristics: ACT Series
    7. 4.7  Prerequisite for Switching: AC Series
    8. 4.8  Switching Characteristics: AC Series
    9. 4.9  Prerequisite for Switching: ACT Series
    10. 4.10 Switching Characteristics: ACT Series
  6. Parameter Measurement Information
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Functional Block Diagram
  8. Application and Implementation
    1. 7.1 Power Supply Recommendations
    2. 7.2 Layout Guidelines
      1. 7.2.1 Layout Guidelines
  9. Device and Documentation Support
    1. 8.1 Documentation Support (Analog)
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Layout Guidelines

When using multiple bit logic devices inputs should not ever float. In many cases, functions or parts of functions of digital logic devices are unused, for example, when only two inputs of a triple-input AND gate are used or only three of the four buffer gates are used. Such input pins should not be left unconnected because the undefined voltages at the outside connections result in undefined operational states. Specified below are the rules that must be observed under all circumstances. All unused inputs of digital logic devices must be connected to a high or low bias to prevent them from floating. The logic level that should be applied to any particular unused input depends on the function of the device. Generally they will be tied to GND or VCC whichever make more sense or is more convenient. Floating outputs is generally acceptable, unless the part is a transceiver. If the transceiver has an output enable pin it will disable the outputs section of the part when asserted. This will not disable the input section of the I.O’s so they also cannot float when disabled.