SNAS558N January   2000  – March 2024 LMC555

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 Switching 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 Low-Power Dissipation
      2. 7.3.2 Various Packages and Compatibility
      3. 7.3.3 Operates in Both Astable and Monostable Mode
    4. 7.4 Device Functional Modes
      1. 7.4.1 Monostable Operation
      2. 7.4.2 Astable Operation
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Flash LED in Monostable Mode
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Frequency Divider
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Application Curve
      3. 8.2.3 Pulse Width Modulator
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Application Curve
      4. 8.2.4 Pulse Position Modulator
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Application Curve
      5. 8.2.5 50% Duty Cycle Oscillator
        1. 8.2.5.1 Design Requirements
    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 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 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)
  • D|8
  • P|8
  • YPB|8
  • DGK|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.3 Operates in Both Astable and Monostable Mode

The LMC555 can operate in both astable and monostable mode depending on the application requirements.

  • Monostable mode: The LMC555 timer acts as a “one-shot” pulse generator. The pulse begins when the LMC555 timer receives a signal at the trigger input that falls below a 1/3 of the voltage supply. The width of the output pulse is determined by the time constant of an RC network. The output pulse ends when the voltage on the capacitor equals 2/3 of the supply voltage. The output pulse width can be extended or shortened depending on the application by adjusting the R and C values.
  • Astable (free-running) mode: The LMC555 timer can operate as an oscillator and puts out a continuous stream of rectangular pulses having a specified frequency. The frequency of the pulse stream depends on the values of RA, RB, and C.