SLFS022J September   1973  – February 2025 NA555 , NE555 , SA555 , SE555 , SE555M

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. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Monostable Operation
      2. 6.3.2 Astable Operation
      3. 6.3.3 Frequency Divider
    4. 6.4 Device Functional Modes
  8. 7 Applications and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Missing-Pulse Detector
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curve
      2. 7.2.2 Pulse-Width Modulation
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curve
      3. 7.2.3 Pulse-Position Modulation
        1. 7.2.3.1 Design Requirements
        2. 7.2.3.2 Detailed Design Procedure
        3. 7.2.3.3 Application Curve
      4. 7.2.4 Sequential Timer
        1. 7.2.4.1 Design Requirements
        2. 7.2.4.2 Detailed Design Procedure
        3. 7.2.4.3 Application Curve
    3. 7.3 Power Supply Recommendations
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.4 Device Functional Modes

Table 6-1 shows the device truth table. For a valid reset voltage condition, use an external pullup resistor to VCC (if using the RESET functionality), or short the RESET pin directly to VCC (if the RESET functionality is not used).

Table 6-1 Function Table
RESET VOLTAGE(1) TRIGGER VOLTAGE(1) THRESHOLD VOLTAGE(1) OUTPUT DISCHARGE SWITCH
LOW Irrelevant Irrelevant Low On
> MAX < 1/3 × VCC Irrelevant(2) High Off
> MAX > 1/3 × VCC > 2/3 × VCC Low On
> MAX > 1/3 × VCC < 2/3 × VCC As previously established
(1) Voltage levels shown are nominal.
(2) CONT pin open or 2/3 × VCC.