SCHS122N November   1997  – April 2024 CD54HC4051 , CD54HC4052 , CD54HC4053 , CD54HCT4051 , CD74HC4051 , CD74HC4052 , CD74HC4053 , CD74HCT4051 , CD74HCT4052 , CD74HCT4053

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  Thermal Information
    4. 5.4  Recommended Operating Conditions
    5. 5.5  Electrical Characteristics: HC Devices
    6. 5.6  Electrical Characteristics: HCT Devices
    7. 5.7  Switching Characteristics, VCC = 5V
    8. 5.8  Switching Characteristics, CL = 50pF
    9. 5.9  Analog Channel Specifications
    10. 5.10 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
    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
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
    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

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PW|16
  • N|16
  • D|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2 Typical Application

One application of the CD74HC4051 device is used in conjunction with a microcontroller to poll a keypad. Figure 8-1 shows the basic schematic for such a polling system. The microcontroller uses the channel-select pins to cycle through the different channels while reading the input to see if a user is pressing any of the keys. This is a very robust setup that allows for simultaneous key presses with very little power consumption. It also uses very few pins on the microcontroller. The down side of polling is that the microcontroller must frequently scan the keys for a press.

GUID-5CF24B6B-D0E5-4724-B2FC-6E200D692AB7-low.gifFigure 8-1 CD74HC4051 Being Used to Help Read Button Presses on a Keypad