SCHS143D November   1997  – April 2021 CD54HC125 , CD74HC125

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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
    7. 6.7 Operating Characteristics
    8. 6.8 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 Balanced CMOS 3-State Outputs
      2. 8.3.2 Standard CMOS Inputs
      3. 8.3.3 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 Design Requirements
        1. 9.2.1.1 Power Considerations
        2. 9.2.1.2 Input Considerations
        3. 9.2.1.3 Output Considerations
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 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 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Related Links
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|14
  • N|14
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.1 Application Information

In this application, a 3-state buffer is used to enable or disable a data connection as shown in Figure 9-1. It is common to see all four channels of a device used together for controlling a 4-bit data bus, however each channel of the device can be used independently. Unused channels should have the inputs terminated at ground or VCC and the output left unconnected.

When the output of the device is active, the data signal will be replicated at the output. When the output of the device is disabled, the output will be in a high-impedance state, and the output voltage will be determined by the circuit connected to the output pin. This circuit is most commonly used when a bus must be completely disabled. One example of this situation is when the circuitry connected to the output is to be powered off for an extended period of time to save system power, and the inputs to that circuitry cannot have a voltage present due to protective clamp diodes.