SCLSA15 May   2024 SN74LVC166A

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
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Characteristics
    7.     13
    8. 5.7 Switching Characteristics
    9. 5.8 Noise Characteristics
    10. 5.9 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Balanced CMOS Push-Pull Outputs
      2. 7.3.2 Latching Logic
      3. 7.3.3 Partial Power Down (Ioff)
      4. 7.3.4 Standard CMOS Inputs
      5. 7.3.5 Clamp Diode Structure
    4. 7.4 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 Power Considerations
        2. 8.2.1.2 Input Considerations
        3. 8.2.1.3 Output 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
      2. 8.4.2 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

8.1 Application Information

In this application, the SN74LVC166A is used to increase the number of inputs on a microcontroller. Unlike other I/O expanders, the SN74LVC166A does not need a communication interface for control. It can be easily operated with simple GPIO pins.

At power-up, the initial states of the internal shift registers are unknown. To give them a defined state of zero, the device can be cleared by applying a low signal to the clear (CLR) input. Alternatively, data can be loaded in directly by switching to load mode (SH/LD = low), then pulsing the clock (CLK) input once.